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Doozer
11-22-2009, 03:02 PM
--This is a piggyback from the wierd bolt hole circle thread, but I thought I'd start a new one.
De-engineering stuff is always fun. Of course, when measuring things, try and see if the designer used inch, metric, polar or rectangular, and anything else I can think of. Also, I consider if the designer used fractional increments to lay things out or decimal. Like I have seen 1.100" used for a bolt spacing on an air regulator bracket that I commonly use. I just prefer to design in fractions, so I would have used 1.125". Which brings up a question....
Is there a preferred method to design in round decimals or fractions, like my example?
I know there are preferred numbers, and that is an interesting subject in and of itself, But what do you guys design in? This is a regional question, so I guess I mean in the US.
--Doozer

John Stevenson
11-22-2009, 03:05 PM
Depends if you have a mill or lathe with fractions on the dial.

.

Doozer
11-22-2009, 03:11 PM
Yeah, I hate lathes with .125 per rev screws!!
A lot of designers I have worked with (uggg) don't even know what a lathe is, so....

--Doozer

gda
11-22-2009, 03:11 PM
I design in hard metric and use GD&T and ISO FaT. (I am in the US).

Often the standard for English drawings was to specify the tolerance through the number of decimal places. So if you dimension everything in fractions you will get everything +/- 1/64" (or +/- 1/32" it's been a long time). If you dim out to three decimal places like you did for 1.125" it would imply +/- 0.005"

The Artful Bodger
11-22-2009, 03:11 PM
Depends if you have a mill or lathe with fractions on the dial.

.

I think my lathe dials are graduated in million-millionths of the distance between the North Pole and the Equator (measured through Paris of course).

Doozer
11-22-2009, 03:14 PM
HARD METRIC.... Ouhhh, that's gotta hurt!

--D

doctor demo
11-22-2009, 03:18 PM
I think my lathe dials are graduated in million-millionths of the distance between the North Pole and the Equator (measured through Paris of course).
This is starting to get close to a (micron) melt down:eek:

Steve

Doozer
11-22-2009, 03:36 PM
You mean Milacron!
;)
Seen that before on another site.

-Doozer

motorcyclemac
11-22-2009, 03:46 PM
I tend to use decimals all the time. I spent the time... long ago when I was a young apprentice machinist ...memorizing the Starett fraction to decimal chart. I used to have some simple and boring machine tasks that left me with a lot of time to stare at the wall. So I memorized the chart. Since then I don't operate in fractions. I do use a flex rule in my apron pocket but when I read it I automatically convert what I see to decimals.

My brother is a cabinet maker and he drives me nuts with is modern shop speak. They operate in metric part of the time..and fractions the other part of the time. The drill 5mm holes.. and cut things with all fractions based on 64ths. Ugh...ok. Seems that all the cnc equipment in his shop is built in Italy and is programmed in metric. However the panel saws are done in fractional. For example a cut might be 36-32/64"

When I engineer a part I think in decimals but typically only to 3 places... 1/4=.250..etc. When I am machining I like to hold tolerances based on the intended use of the part. If I am doing gun work..some things should hold 1 tenth...others are +/- .010. Some things matter others...not so much.

We used to have a fellow in a shop I worked in that was a bit of a slob that didn't last too long. We used to say that he worked to the "welder's fit"...+/- a quarter inch. Oddly he was also known for producing parts with the "Black and Decker" finish...suggesting everything looked like it had been completed with an angle grinder. He was a former equipment fabricator and wore coveralls rather than a shop apron..and used a Stanley 20 foot tape in his pocket rather than a flex rule. Nice chap..but never could adopt the machinist mind set.

Cheers
Mac.

wierdscience
11-22-2009, 04:44 PM
The only prints I have seen with dems in fractions are very old ones,think piston steam era.That and wood working prints.

In CAD I set dems at .0000" and spec the tolerances in notation.

There is a function where dems can be done in dual system either inch/metric or fraction/decimal inches.

If a person works in the metal trades for any serious amount of time they should commit to memory decimal equivilents at least to 16ths.

Ernie
11-22-2009, 05:37 PM
My micrometers are decimal so I use decimal for lathe work etc. but my woodworking scales are all fractional so I use fractions for woodworking.
Ernie

motorcyclemac
11-22-2009, 05:58 PM
The first shop I worked in had a bunch of old blueprints for parts we made. The prints were uh... DARK BLUE..with white printing. They were drawn by the former owner of the shop..using a homemade t-square and set of metal triangles. He dimensioned all of them in fractions and the tolerances were often +/- 1/64th then in brackets he would hand write " HEAVY or heavy" or "LIGHT or light". Much of the machine work he did..was in the 1920's to the 1950's when he owned the shop. He would use calipers and a flex rule for much of his measurement that was over an inch. Best I knew was that he had a 0-1" micrometer and a 0-6 vernier caliper. Those instruments and his battle worn flex rule lived in a glass case in the office on the wall. The corners of his flex rule were worn from measuring parts on the lathe...with it spinning.

My father was formerly a draftsman back in the pencil and paper era...and thus he was asked to re-draw many of the old drawings to convert the measurements to conventional decimal figures and include proper tolerances. We ran into some issues as we tightened up the tolerances on some of the machine parts and suffered some need to loosen them up later. We tried to uniformly apply common tolerances to parts. For example a shaft might have been cut to 1.125 +/- .001. His machinery required some extra room to function. We discovered that +/- 1/64 "light" meant .025...in some cases.?!?!?? In other cases "LIGHT" meant .010.. :-)

Cheers
Mac.

darryl
11-22-2009, 06:01 PM
The answer is pretty much tied to the measuring instruments and control methods used. I have yet to ditch the old inch system for woodworking, since my measuring tapes are marked in sixteenths, etc. On the metalworking machines, I'm lucky that they are all calibrated in thous, so I can still relate inches and fractions thereof to what my mind thinks of as distance. I'm not too bad at mentally converting 1/32s etc into thousandths, so I feel that whether decimal or fraction it's still the same system.

Once it gets to metric, I don't like to make the conversion. If my leadscrews were metric, the dials marked out in metric, and I had metric calipers, micrometers, and tape measures- I could use it as a stand-alone system. That would be ok also, but- as I go out to buy materials, I get so many feet of this, a dozen of these bolts, some 1 1/2 inch angle, 2 inch pipe, and 4x8 sheet goods.

The Artful Bodger
11-22-2009, 06:20 PM
This country is supposed to be metric but a lot of stuff is just 'nominal', aluminium round is sold as 'metric' but it is really the closest imperial which may or may not be a problem. Nuts I buy from the hardware store are metric internal size and threads but the outer of the nuts are still imperial!

Wallboard is still commonly known by its imperial sizes "8x4" for example but on the docket it will be printed out as some awkward metric number.

What really frustrates me though is the metric divisions on my lathe dials. The cross slide is calibrated for diameter and is engraved for 4mm per full turn (i.e. 2mm of carriage travel). The graduations are every .04mm which makes it impossible to label ever .1mm and I find it near impossible to interpolate!

clutch
11-22-2009, 06:28 PM
The only prints I have seen with dems in fractions are very old ones,think piston steam era.That and wood working prints.

The other day, management was cleaning out the obsolete parts drawing files. I picked up a drawing from the dumpster. Dimensioned to 1/64" with a few decimal call outs.

Revision date 1947. Wish I had kept it for wall art.

Clutch

oldtiffie
11-22-2009, 06:34 PM
--This is a piggyback from the wierd bolt hole circle thread, but I thought I'd start a new one.
De-engineering stuff is always fun. Of course, when measuring things, try and see if the designer used inch, metric, polar or rectangular, and anything else I can think of. Also, I consider if the designer used fractional increments to lay things out or decimal. Like I have seen 1.100" used for a bolt spacing on an air regulator bracket that I commonly use. I just prefer to design in fractions, so I would have used 1.125". Which brings up a question....
Is there a preferred method to design in round decimals or fractions, like my example?
I know there are preferred numbers, and that is an interesting subject in and of itself, But what do you guys design in? This is a regional question, so I guess I mean in the US.
--Doozer

Doozer.

I think I might have some bad news for you.

Like I have seen 1.100" used for a bolt spacing on an air regulator bracket that I commonly use. I just prefer to design in fractions, so I would have used 1.125".

1.100 x 25.4 = 27.94mm

So, if I round that out to 28.00mm it is actually 28.00/25.4 = 1.1024 which "only" about 2 1/2 thou "off" and well within tolerance for that sort of application.

Perhaps the "metric demon" has snuck up when you weren't looking and "gottcha".

Re-check it with a metric rule.

Mcgyver
11-22-2009, 06:42 PM
I design in fractions expressed as decimals. For me fractions are more intuituive way to design, and there's little point in specifying an od of say .300 when your collet is .3125

Mcgyver
11-22-2009, 06:55 PM
Duplictae, sorry

brian Rupnow
11-22-2009, 07:03 PM

J Tiers
11-22-2009, 07:03 PM
Can this actually be serious?

Fractions?

Just say no to fractions. Rational they may be, but not rational to use.

I went through all that with the wood shop at the old place 15 years ago.... they demanded tolerances of 1/32, and QC demanded that they should not be able to get a dollar bill thickness into any cabinet gap. Obvious collision there.

I was tempted to let it happen, but cabinets that were angles turned up way off dim, and everyone complained. I investigated and found the drafting department had snapped to a 1/32 grid in order to conform with the woodshop stated tolerance. You can imagine what that did to lengths on cabinets with shallow angles.

So after everyone quit bouncing off the ceiling, we agreed that all the CNC stuff worked fine in thous, and we could draw to thous, so we would make all dims to thous, and they would input them to thous.

Surprise, everything fit, and the dollar bill didn't go in.

Now, these days of course, there would be a bigger problem, because the new thinned and lightened dollars would slip in where the old ones don't. :eek:

oldtiffie
11-22-2009, 07:34 PM
I design in fractions expressed as decimals. For me fractions are more intuituive way to design, and there's little point in specifying an od of say .300 when your collet is .3125

Given that 5/16" = 0.3125 x 25.4 = 7.94mm a 7>8mm ER collet would easily handle that as it has 1.00mm gripping range of 7.00mm (0.276") to 8.00mm (0.315").

All of my ER-32 metric collets are marked with the inch fractional range that they handle.

Perhaps "inch" ER collets are the answer as they are more versatile than C5 (metric or inch).

I have machines and accessories that are metric C5 but I use the "John Stevenson Special" C5>ER-32 adaptor in my C5 female receivers and so I cover all bases.

Fractions in machine or fitting work seem to be a hang-over from the days of machinists using steel rules and frictional (and "spring") calipers.

"Wood" people and metal fabricators (in the "non-metric" ie "inch" countries) who commonly use rulers and tapes use the classic "advance by halves" rules/tapes (1, 1/2,1/4, 1/8, 1/16, 1/32, 1/64, 1/128) as it is easier to "halve" a distance or dimension "by eye". "Rounding up" from factional to decimal is not so bad but the reverse is more likely to have more and/or larger errors.

Once a digital device or machine is involved the fractions have to be converted to decimal. Even "inch" machines have the dials calibrated in decimal ("thous") as do analogue micrometers. All calculations are done in decimal.

As is the case with many people who live in countries that were "inch" and were later "metricated" (as I was and am in OZ) I was brought up on inch and converted to metric. Many of us are quite "bi-lingual" as regards working in or converting to or from one system to the other pretty well seamlessly and automatically.

I can work in inch and fractions and decimal equivalents but I far prefer the consistency of the metric system.

I have neither right nor reason to ram my preference down anyone else's throat as what ever works for someone (every one/ any one) is the right system for them.

rockrat
11-22-2009, 07:48 PM
It all depends on what I am building. I built a stand for the TV and it was dimensioned in fractions, the shop plans were dimensioned in fractions, my house plans are dimensioned in fractions.

Now, the yard landscaping was dimensioned in feet, the old plant layout where I once worked was dimensioned in feet with half foot intervals noted (but rarely used).

Jigs, fixtures and the such have been dimensioned in decimal except when I knew the mold maker would be fitting things on the fly.

Honestly, it just depends. If I had to quickly make a stand I would say that either the final fit controls the dimensions used or the medium and ability to remove/add the medium controls the dimensions used.

rock~

smalltime
11-22-2009, 08:04 PM
Gotta jump in on this one.

GUYS!
We are Machinists. We work in decimals. If you want to work in fractions, go over to the woodworking sites. I convert EVERYTHING to decimals as a matter of course.
As far as engineers are concerned: Don't be concerned. Convert the drawing into decimals and do the job. Show me a machine that has 1/64ths on the dial. If you have a metric dial, then convert the drawing to metric. This will save time and money.

wierdscience
11-22-2009, 08:43 PM
I think Brian may have nailed it on the head,draw to the limits of the labor.

Doozer
11-22-2009, 08:48 PM
Thanks for all the good replies. That air regulator bracket bolt hole spacing that measured 1.100" could have been 28mm for sure. It is the 1/4 npt Norgren F-R-L unit from McM. The bracket is plastic and the holes likely have some draft, to hard to tell. What's .0025" between friends with a plastic bracket :).
I hear what you are saying about the application. Wood and welding fab I would use fractions. But I was talking about drawing/designing metal or such things that we would make on a mill or a lathe. I know by the number of decimal places that there is an implied total tolerance, but that's not what I was getting at. I meant more of the design of spacings on stuff that is usually rather arbitrary like a bracket or holes on a hinge or dowel pin spacing. Like, would I put a set of holes .750" apart or .800"? Personal choice would be to use the .750". If the .800" made more sense from a design stand point, would I use .813" (13/16) to stick with my tendency to favor fractions? I guess I would.
I have memorized most of the decimal chart and most of the drill sizes from the tap chart, and I guess I just like to use the conversion from fractions to decimal because I do think it is neat as far as mathematics goes. It is not something someone off the street would know, so I guess I hold the notion of expressing fractions as decimals as an intellectual thing, that adds esteem to the trade or the job I am doing at the time.
I think of measuring in fractions as coming from carpentry. I like carpentry very much, and carpentry teaches some very good lay out and fabrication skills. I believe every metal fabricator and machinist and engineer should take some carpentry classes. I believe the skills transfer remarkably well to these professions. I like to pay homage to the trade of carpentry by using fractions in my designs, but I like to convert them to decimal to show respect for the machining trade, which I enjoy so much.
--Doozer

john hobdeclipe
11-22-2009, 08:48 PM
When I first started to work in a furniture factory, we measured length, width and thickness to the closest 1/16 inch. Other aspects of a piece, such as dowel hole locations were done by fitting to an approved master pattern. This was precise enough for upholstry frames.

Later, in the bicycle business, I was exposed to and started learning to metric measurements.

Then, back in the furniture business, at a major player in the high end case goods market, we managed to get by with + or - 1/32 inch and a lot of wood putty (there's a reason why furniture makers push dark finishes.)

Still later, I found myself setting up and operating German built Weinig moulders, which are all equipped with metric scales and dials. We would always get drawings dimensioned in fractional inches, we were supplied with dial calipers graduated in decimal inches, and used these to set up machinery graduated in metric. I soon became very adept at mentally converting between the three.

Nowadays, whenever I'm drawing / building something in metal I think in decimals and whenever I'm working with wood I think in fractions, and often find myself using them both at the same time without thinking about it.

Carld
11-23-2009, 08:41 AM
Well Doozer, if your talking about just metal work on a lathe or mill I always design in decimals and the only variation is for drill size and thread size. My lathe and mill is decimals and there is no reason to design in fractions and then either mentally or physically convert the fraction to decimal to do the work. If you design in fractions and work in decimals how do you indicate +/- tolerances? The smallest fraction normally used is 1/128 which is .0078". So, do you design with fractions less than 1/128"? Of course if the smallest fraction you use is 1/128 then you shouldn't have trouble holding that tolerance on a lathe or mill. Wood working I use fractions. Fabricating with structural steel and welding I use fractions. Doing machine work I use decimals.

EDIT: I tried to post this last night but my service went down.

moldmonkey
11-23-2009, 10:28 AM
Guys, he's not talking about dimensioning or tolerances but location of hole spacing, etc.

I get to design the stuff I build for work and I try to space holes & bolt patterns nominal fractional distances apart, if I can help it in 1/8 increments or larger. Eg., it would be tapped holes 3.125" apart not 3.100" or 3.150". Most standard (non-metric) stuff I have reveresed engineered is the same.

Paul Alciatore
11-23-2009, 10:37 AM
I use the LRCH. Since stock is generally available (in the US) mostly in fractional sizes, I have a chart that converts fractions to LRCHs. Sinch the LRCH is the smallest division known to man, conversion to metric is simple but you need a calculator that has an infinite number of decimal places.

Evan
11-23-2009, 10:46 AM
I tend to use decimal fractions, .032, .0625, .125, .250, .312, .375, .5, .625, .750 etc.

I also use metric and am comfortable in either system or even a mix of both. It's just units either way. Actual ratios aren't of much use to me.

Doozer
11-23-2009, 11:09 AM
Yes Moldmonkey, that is what I am talking about.

I try to communicate like I am writing a college paper, that is...
State the problem,
Give an example of the problem,
Give another example, stated a different way,
And restate and summarize the problem.
Still some people have their own version of what they think they read.
Thank you for understanding what I was asking Moldmonkey :) .
And thank you to others for their insightful input.
--Doozer

Circlip
11-23-2009, 11:10 AM
Who "Designs" all the little pictures that acompany dimensions for geometric tolerancing, and have we REALLY lost the will to live when deciphering them??:confused:

Regards Ian.

Dan Dubeau
11-23-2009, 11:44 AM
Hey Brian, Don't throw all of us young guys in the trash pile :D . I'm a designer, inspector, and machinist, It just depends on the day. I work in Inch, metric, decimal, fraction, eyeball, eyelash, whatever the job calls for. When designing (using cad) I pay attention to the methods of manufacture, and to critical dimensions, and call them out as such. I have never done any manual drafting, it's all been CAD. But I've always treated it as just another manufacturing tool. And while designing to think about how, and what will be used to make the part. It's all too easy as a fresh grad (wow 7 years ago now) to wind up designing things, making them ten times harder to build than they need to be. All the while making Machinist friends as you go ;) . I've had a few of those moments, but thankfully not so many anymore, as now I'm mostly on the other side of the coin (print).

Growing up, metric was taught in school. Shop class was taught in inch fractions. College was inch decimal/metric. I took well to all types, and use them interchangeably day in day out. although I much prefer Inch decimal for working in the shop (as all machines are graduated this way), but for cad work, I prefer metric. Woodworking I revert to inch fractions. Carpentry is fractions heavy/light.

I always get a laugh when I get some cad from a customer in metric, but the nominals for things such as hole sizes/pitch/feature are 12.7, 38.1, 50.8, etc. :D

Carld
11-23-2009, 01:04 PM
Doozer, I went back and read all of your posts and none of them were presented in the form of a "college paper". I did understand that you were talking locations of holes,etc. but fractions, for the most part, have little place on a modern print.

It's nice that you memorized the fraction/decimal chart and that helps at times. The fact is if you design something in fractions and give the print to someone to make the part they will convert to decimals so it's best to draw with decimals or metric as you choose. Most machinists will convert metric to imperial decimals.

If you personally go to the mill or lathe with a print in fractions you will have to mentally, since you memorized the chart, convert to decimals to do the job. The lathe and mill wheels are in decimals or metric and a DRO is decimals or metric.

That is the point that most of us are making. YOU asked what we do and prefer and we told you. I don't think any of us misunderstood your intent. I think that Brian did an excellent job of discussing the issue.

mochinist
11-23-2009, 01:30 PM
Doozer, I went back and read all of your posts and none of them were presented in the form of a "college paper". I did understand that you were talking locations of holes,etc. but fractions, for the most part, have little place on a modern print.

It's nice that you memorized the fraction/decimal chart and that helps at times. The fact is if you design something in fractions and give the print to someone to make the part they will convert to decimals so it's best to draw with decimals or metric as you choose. Most machinists will convert metric to imperial decimals.

If you personally go to the mill or lathe with a print in fractions you will have to mentally, since you memorized the chart, convert to decimals to do the job. The lathe and mill wheels are in decimals or metric and a DRO is decimals or metric.

That is the point that most of us are making. YOU asked what we do and prefer and we told you. I don't think any of us misunderstood your intent. I think that Brian did an excellent job of discussing the issue.I thought it was pretty clear what he meant, he's not talking about putting any fractions on the actual print.

juergenwt
11-23-2009, 02:11 PM
What a "mess" we are in - thanks to our late Pres. Reagan.
We teach Inches, Gallons, Pounds, Millimeters, Fractions, deg. Fahrenheit, deg Celsius, Feet, Yards, Kilometers, Liters, Quarts, Pints and ounces. Work in inches, design in metric, prefer fractions, use half and half, tolerance in gizmos and check with my eye scale. Convert to and from all of these. Any wonder we are loosing the export race with the rest of the industrial world. Just when are we going to end this madness or are we waiting for the last US Manufacturer to close? It makes you cry out for some political leadership. How soon?
A check of all the above posts will justify what I just wrote.

Carld
11-23-2009, 04:19 PM
what ever. He asked I said. Conversation over.

JMS6449
11-23-2009, 07:29 PM
I use the LRCH. Since stock is generally available (in the US) mostly in fractional sizes, I have a chart that converts fractions to LRCHs. Sinch the LRCH is the smallest division known to man, conversion to metric is simple but you need a calculator that has an infinite number of decimal places.

No comments? I don't believe it

tattoomike68
11-23-2009, 07:47 PM
My micrometers are decimal so I use decimal for lathe work etc. but my woodworking scales are all fractional so I use fractions for woodworking.
Ernie

Same here, I still use calipers for wood working. I used to work in a foundry pattern shop so we tried to do real close work despite the shrink factors.

I dont have a problem with metric at all, its all the same to me. just make \$hit fit right.

oldtiffie
11-23-2009, 08:18 PM
You are right Mike.

Pattern shops use "shrinkage rules" which are calibrated for the differing shrinkage rates of different metals.

We had them in a shop I was in as an Apprentice. It was the "thing to do" to swap an Apprentices rule a shrinkage rule. It was either hilarious or disastrous. We occasionally did work for the Pattern Shop in our small foundry (larger stuff was contracted out).

http://www.nonesuchtools.com/pmkr/shrink.html

http://chestofbooks.com/crafts/mechanics/Mechanical-Processes/237-Shrinkage-Allowance.html

Michael Moore
11-23-2009, 09:15 PM
I've found the occasional "can't be anything but inch" part on vintage Italian bikes which are nominally metric.

If you are going to work in fractions you'll need one of these:

http://www.eurospares.com/graphics/metalwork/dialindicator.jpg

cheers,
Michael

wierdscience
11-23-2009, 11:22 PM
What a "mess" we are in - thanks to our late Pres. Reagan.
We teach Inches, Gallons, Pounds, Millimeters, Fractions, deg. Fahrenheit, deg Celsius, Feet, Yards, Kilometers, Liters, Quarts, Pints and ounces. Work in inches, design in metric, prefer fractions, use half and half, tolerance in gizmos and check with my eye scale. Convert to and from all of these. Any wonder we are loosing the export race with the rest of the industrial world. Just when are we going to end this madness or are we waiting for the last US Manufacturer to close? It makes you cry out for some political leadership. How soon?
A check of all the above posts will justify what I just wrote.

The mess started with Clinton as we now turn out grads who cannot read a ruler,inch,metric or otherwise.

tattoomike68
11-23-2009, 11:38 PM
You are right Mike.

Pattern shops use "shrinkage rules" which are calibrated for the differing shrinkage rates of different metals.

We had them in a shop I was in as an Apprentice. It was the "thing to do" to swap an Apprentices rule a shrinkage rule. It was either hilarious or disastrous. We occasionally did work for the Pattern Shop in our small foundry (larger stuff was contracted out).

http://www.nonesuchtools.com/pmkr/shrink.html

http://chestofbooks.com/crafts/mechanics/Mechanical-Processes/237-Shrinkage-Allowance.html

Everything about working in a foundry was just cool as hell, the massive machine shop (lots of big lathes), the sand system, the molding machines themselves were trick. The scrap yard was a gold mine of metals all to itself.

to bust huge casting we had a 5 inch plate on the ground and would pick up big parts and drop them to bust them so they could go to our crusher.

it was just tons of fun.

If any young guys want to learn some stuff get a job at a foundry, its tough, hot , and dirty. Iv seen big tough US marines who did not make it a whole day there. I always told the noobs "Welcome to hell!" by the time we sent them to get a metal stretcher and a bucket of steam and we laughed at them hard they were ready to bail out. :D

juergenwt
11-23-2009, 11:56 PM
Sorry wierdscience - but in the 70's when all was set to put the nation on the road to an complete and orderly transition to the metric system, Pres. Reagan pulled the biggest blunder of his life by cutting all funds for the change to metric. Today's mess is the direct result of that action. Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector. The latest report show a 35% decline in just the last 10 years.

wierdscience
11-24-2009, 12:02 AM
Sorry wierdscience - but in the 70's when all was set to put the nation on the road to an complete and orderly transition to the metric system, Pres. Reagan pulled the biggest blunder of his life by cutting all funds for the change to metric. Today's mess is the direct result of that action. Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector. The latest report show a 35% decline in just the last 10 years.

OMG! That's funny,funds to change to metric,good god man join up with Albore:D :D

tattoomike68
11-24-2009, 12:11 AM
Sorry wierdscience - but in the 70's when all was set to put the nation on the road to an complete and orderly transition to the metric system, Pres. Reagan pulled the biggest blunder of his life by cutting all funds for the change to metric. Today's mess is the direct result of that action. Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector. The latest report show a 35% decline in just the last 10 years.

Thats just nuts, American machinist make metric parts every day, its the lazy over paid and underworked union bums that screwed the us manufacturing. some button pusher thinks he is worth \$30 an hour.

I bet 50% of all the part I ever made were metric, I like metric its easy and fast math wise.

Our medical industry is 100% metric so I dont see where you are coming from.

wierdscience
11-24-2009, 12:27 AM
Thats just nuts, American machinist make metric parts every day, its the lazy over paid and underworked union bums that screwed the us manufacturing. some button pusher thinks he is worth \$30 an hour.

I bet 50% of all the part I ever made were metric, I like metric its easy and fast math wise.

Our medical industry is 100% metric so I dont see where you are coming from.

Exactly,also since the Brits and Aussies went metric long ago why has thier industry also gone in the crapper along with ours?

It has noting to do with what system of measurement is used,it's all about attitude.Mommy and Daddy raise their children to be doctors,lawyers and accountants these days,not machinists and weldors.

SVS
11-24-2009, 01:52 AM
I'm pretty sure Reagan is not to blame for the 70's....He didn't get elected til 1980, and winning the Cold War and fixing Carter's hangover is credit enough to any human.

People claiming we are not Metrified aren't really watching. Your groceries are labeled both ways, you drive in mph, survey land in acres and sections, but try buying any machine built in last ten years not metric from ground up.

I think 75% of the problem was old farmers and mechanics (me included) crying about buying a new set of "them furrin wrenches", but 30 years from now I bet McMaster Carr will be the best source for those "antique SAE bolts". As inch standard equipment trickles back to the steel mill the mainstream market for inch hardware will die with it. Same type of thing is gradually taking place in every segment.

The machines I really cuss are the hybrid SAE here...metric there mongrels.

Scott

Walter
11-24-2009, 02:57 AM
I have no problem or issue working fractional / decimal. Easy as pie to jump back and forth. Easier still to work in decimal with a fractional overtone and I usually do, especially when designing. I agree totally, dimension as called for. No tenth calls on the doghouse design and conversely no 1/8th inch calls on a bearing surface.

If it's metric it gets converted to decimal and thats that, all metric notations forever forgotten. I think in inch measurements, not centimeters or millimeters. I see inch measurements, not metric. It'll be a cold day in hell when I willingly work in metric measurements.

Peter N
11-24-2009, 02:59 AM
I have a CAD file on my computer of a moulded part for the fuel pumps on a Boeing 747 that we made a few years ago. The drawing is all imperial as you might expect, and has both fractions and decimals.

Peter

SVS
11-24-2009, 03:48 AM
Easier still to work in decimal with a fractional overtone and I usually do, especially when designing.

That's the perfect way to explain my natural inclination. Given a choice on bolt spacing type jobs, I like to use 1/4" or 1/2" as finest increment. This fits my work which is usually larger welded fabrication with machined details, and/or nominal inch size shaft/bearing/pin/bushing repairs. I rarely need better than +\-.003 on the lathe, and I do an embarrassing percentage of my heavy milling with a tape measure.

Scott

tattoomike68
11-24-2009, 04:02 AM
I have a CAD file on my computer of a moulded part for the fuel pumps on a Boeing 747 that we made a few years ago. The drawing is all imperial as you might expect, and has both fractions and decimals.

Peter

Thats not too uncommon but the crappy prints that have 1" + 1.250" = 2.26502 and the math dont work, and the print is wrong I take note and dont make a part ill I have clarification. (in this day and age cover you butt and keep a note book)

I found errors on prints from Boeing and other folks who could not add two numbers.

All the errors were from incremental dimensioning, where baseline dimensioning is the olny way

tattoomike68
11-24-2009, 04:07 AM
I do an embarrassing percentage of my heavy milling with a tape measure.

Scott

Nothing wrong with that scott, the tape dont lie. I use a 6 " starret ruler on the lathe when roughing. I know with practice most guys can hold +/- .010 or less with a tape measure that they know and like.

Peter N
11-24-2009, 04:11 AM
I found errors on prints from Boeing and other folks who could not add two numbers.

Actually you're dead right there Mike. I just had a quick trawl through the old files on the CAD computer to dig this drawing out, and it's FULL of anomalies.
I'll post a small screen dump of (part of) the drawing later, but I've just noticed that it also has some metric hole dimensions on it, and on loads of dimensions that are < 1", they have omitted the leading zero and the decimal point!
We also have the 3D Cad model to refer to - so the mistakes are obvious - but very, very, sloppy nonetheless.

Peter

This is a partial view of the drawing, note the metric hole dims. and the lack of decimal points/leading zeros:

http://www.btinternet.com/~p.neill/747_1.jpg

This is the 3D CAD file:

http://www.btinternet.com/~p.neill/747_2.jpg

And here are some old pictures of the moulded part. As an aside, the material is a 40% carbon fibre filled polyphthlamide, and we were the first people outside of the US to use this and we had lots of people from the corporate headquarters of EMS-Grivory in Switzerland all over us when we moulded it, as they hadn't actually seen it used in an application before.

http://www.btinternet.com/~p.neill/747_3.jpg

Circlip
11-24-2009, 04:31 AM
Britain DIDN'T go Metric, we did a partial changover. In the Textile machinery company I worked at the time in the 60s, we had to become bi-sexual cos all the drawings of machines going back to the late 18's and early 1900's weren't going to be converted, OR could have been. (Just look at todays problems with dimensioning).

Even in later years, when Metrics should have been the norm, in my involvement in the Electronics industry, although the PCB's were in the main Metric, Silicon Valley buggered it up with INSISTING that all the pitching for pre-forms like transistor legs and IC spacing were maintained at 2.54, 5.08 12.7 etc. COS THEY COULD.

Just to show that the changeover for us did go spheroids up, who decided to teach Dressmaking and Knitting dimensions to kids as part of the Education system.??????

Regards Ian.

tattoomike68
11-24-2009, 04:48 AM
Actually you're dead right there Mike. I just had a quick trawl through the old files on the CAD computer to dig this drawing out, and it's FULL of anomalies.
I'll post a small screen dump of (part of) the drawing later, but I've just noticed that it also has some metric hole dimensions on it, and on loads of dimensions that are < 1", they have omitted the leading zero and the decimal point!
We also have the 3D Cad model to refer to - so the mistakes are obvious - but very, very, sloppy nonetheless.

Peter

When I was messing with bad prints I was working as the machine tool repairman at a screw machine shop, when all machines were running fine I was the part time toolmaker and when that was done I was stuck in the hell known as "THE INSPECTION LAB" sorting good and bad parts. :confused:

the THE INSPECTION LAB sucks big time, when you trash parts you make the boss mad and the workers. I threw lots of trick stuff in the scap bin, it did not make the print.

J Tiers
11-24-2009, 09:26 AM
Sorry wierdscience - but in the 70's when all was set to put the nation on the road to an complete and orderly transition to the metric system, Pres. Reagan pulled the biggest blunder of his life by cutting all funds for the change to metric. Today's mess is the direct result of that action. Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector. The latest report show a 35% decline in just the last 10 years.

Beans.....

I work in metric as much as decimal inch (but never in fractions, aside from traditional stock sizes).

You cannot buy things at the grocery store without running into metric. The 2 litre bottle for the most in-your-face example. There are many, many others.

The military works in metric..........

Paul Alciatore
11-24-2009, 10:12 AM
Britain DIDN'T go Metric, we did a partial changover. In the Textile machinery company I worked at the time in the 60s, we had to become bi-sexual cos all the drawings of machines going back to the late 18's and early 1900's weren't going to be converted, OR could have been. (Just look at todays problems with dimensioning).

Even in later years, when Metrics should have been the norm, in my involvement in the Electronics industry, although the PCB's were in the main Metric, Silicon Valley buggered it up with INSISTING that all the pitching for pre-forms like transistor legs and IC spacing were maintained at 2.54, 5.08 12.7 etc. COS THEY COULD.

Just to show that the changeover for us did go spheroids up, who decided to teach Dressmaking and Knitting dimensions to kids as part of the Education system.??????

Regards Ian.

You can't really blame the electronic types on that. They had billions of parts out in the field that were already designed in inches. The 1/10 inch grid was so standard in the electronics world that I would bet that even good old metric Europe did much of their work with it. And the Japanese also were following suit and making ICs and such to fit a 1/10 inch grid. This was purely for the simple and practical purpose of maintaining the vast number of equipment that was in place in the world.

Today, with new and ever smaller series of ICs constantly appearing and increased competetion and innovation from both the Pacific countries and Europe, you do see that most new electronic parts are designed to metric dimensions. It has been a slow process, and in the process I have seen many electronic boards that contained a mixtuer of English and metric parts. I have done PCB layouts and I can tell you that mixing the two systems of measure there is perhaps a lot easier than in mechanical designs. Even now, many layout programs start out with the old 1/10 inch grid. But you simply lay metric parts down on it and the traces just snap to the parts, not to the grid. Of course, you can specify a millimeter grid and if you know you will be using most or all metric parts, it is best to do that up front. Or just set it as your default. Then, if you need to include any inch parts, that works just as well as metric on an inch grid.

In another 10 years or so, I suspect the electronic industry will be mostly metric. The parts manufacturers are there now with the old parts still available for those who want/need them. Most new, cutting edge design is there. It is just a matter of getting the remainder of the board designers to make the switch. And this will happen as they need to use a greater percentage of parts that are only or primarily available only in metric.

Besides, 2.54, 5.08, and 12.7 sounds quite metric to me. Just as metric as 0.7 or 1.5. And you will not see electronic parts settle on a 1 mm grid and stay there. We are probably already past that point in our everlasting persuit of smaller and smaller devices. 0.7 mm, 0.5 mm, and even smaller spacing is already here and it will continue to go down. And the new sizes WILL be based on metric.

Evan
11-24-2009, 10:58 AM
I bet 50% of all the part I ever made were metric, I like metric its easy and fast math wise.

All the parts you made were metric. I have no problem measuring any parts using my metric measuring tools. I have everything from metric calipers to several dial indicators including a Tesa that is calibrated in microns. Also 4 micrometers from 20 mm to 150mm. Metric height gauge and rules, metric thread gauges and weigh scales. Metric taps and dies. My South Bend will cut metric threads and my CNC works in UNITS only.

juergenwt
11-24-2009, 03:16 PM
J Tiers - Are you thinking in metric?
Yes, people can do metric work but they can not think in metric.
That has to start in our schools. That is where we should have started years ago with a complete change to metric. Nothing else!
Read all the above posts. They all proof my point! What a mess we are in!
As for Pres. Reagan - all I said that he killed the drive to an orderly and complete change to metric.
As far a metric products in stores go, with a few exceptions we are still in the inch, pound and gallon stage. Easy to see on the package i.e. one pound/453 grams.
But the main point I am trying to make is that the rest of the world still believes the US can not make anything in metric and they are not buying inches.
Last week there was a story in a Chicago paper about exchange students from the rest of the world studying in US schools. They had one common observation: How come the US is still hanging on to such an obsolete system of measurements?
NASA to the applause of all the engineers and scientists announced just a short time ago that all future undertaking would be in solid metric. Now the media will have an even tougher time to keep dumbing down the people or NASA will have to double the size of it's public relations office.
Just for laughs: Urinal in a men's room - 1Gal./3.78 Liters per flush or my own observation at the Chicago International Tool Show some years ago....listening to a salesman explaining to some Japanese visitors:" This machine is accurate to within +/- 5mm". Guess how many he sold?
Ps.: I am sure there are some in the US who have adopted the metric system and are able to think in metric, but very few.

Evan
11-24-2009, 04:11 PM
I grew up in the US but my father was a science teacher and part time researcher. He made a point of always using metric in his classroom and it was de rigour for his scientific explorations. Unlike the vast majority of Americans I learned it along side the imperial system and have always been conversant with both. I switch back and forth depending on which unit sizes produce the easiest to work with numbers for the job at hand. When I was young and there were no CAD programs I routinely did my drawings on a scale of one centimeter to the foot. It makes a very nice scale for human size objects that need to be drawn on a sheet of A4/letter size paper.

motorcyclemac
11-24-2009, 05:33 PM
I guess that is the root of the problem. I don't "think" in metric. I can work in it..but I think in inches / feet. A part that is 4.500 inches long is something I can visualize in my head. 15.5 centimeters or 200mm doesn't click in my head like inches or thousands of an inch.. It has always been foreign to me. Just like driving in Canada. I hate it. 100 Km/h doesn't jive with my 60 mph. Since there is an easier more comfortable system that I am familiar with ...I use it. If we totally abandoned it in favor of metric..and I had no fall back..I would adapt. But that transition would be a pain..as I would have to think about every measurement... for a while. Having my motorcycle speedometer go to 320 Km/h would look wierd.

Cheers
Mac.

J Tiers
11-25-2009, 12:15 AM
J Tiers - Are you thinking in metric?
Yes, people can do metric work but they can not think in metric.
?
Ps.: I am sure there are some in the US who have adopted the metric system and are able to think in metric, but very few.

Yes I do. I can estimate large and small distances in either metric or inches, and generally can use metric or foot/inch as I please without needing conversions to have a sense of the actual distance.

I am not good with estimating litres, but then I don't do well with gallons either.

I always use the calculator for real conversions if the conversion matters. My machines do not think in metric, they have inch dials and screws, so I do need to do conversions quite a bit.

I suspect that is much of the issue. Until CNC, metric was hard to implement. Every machine would have had to be scrapped, since re-doing it for metric would cost a prohibitive amount. An inch leadscrew for a Cincinnati lathe is list at something crazy like \$5000, much more than the machine is worth, and you'd need one leadscrew, many gears, and two feed screws. Cheaper to scrap it and send the work to china.

Evan
11-25-2009, 03:53 AM
Every machine would have had to be scrapped, since re-doing it for metric would cost a prohibitive amount.

That was a much used argument here until somebody pointed out that DROs don't really care what system they read out in. Our largest local job shop has mostly inch manual machines still but make most of their parts to metric specs. Things like Caterpillar heavy machinery like the backhoe I used this summer have been all metric for decades.

11-25-2009, 04:37 AM
I kinda like designing in zepto parsecs. Makes a bit of a change and it loosens up the checker. Especially if you don't tell him what measurement sytem of units the zepto parecs are calculated from.

oldtiffie
11-25-2009, 04:55 AM
Here is something to think about:
http://en.wikipedia.org/wiki/Metrication_in_the_United_States

http://en.wikipedia.org/wiki/Metrication

So, as Jergen (Sp?) says, if the USA wants to stay behind the rest of the world - and get further behind as time goes on - making it increasingly hard to change and catch up - it has a lot of soul-searching to do.

It should have been a "sellers market" for the US while the US\$ is so low against its competitor currencies - but, again, it has largely "missed the boat".

Once the US\$ appreciates and both interest rates and inflation "kick in" the problem will only get worse.

The US is part of the world economy as regards trading etc. It is not as much the "pace-setter" as many hope or imagine. It will require a lot more effort by the USA to meet customers needs in a competitive environment rather that set the standards and costs and just wait for the customers to deal with the USA on the USA's terms - which won't happen.

Using international units is the way to go.

Moaning, groaning and "rubbishing" everything and everybody that doesn't comply with the way some in the US see themselves and the world at large is, at best, counter-productive.

There is going to be some very fierce competition for business as the world works its way out of the economic hole it is in.

Recognising that the metric system is here to stay - and will not go away - and adapting is a good first step along what may be a long and painful road.

Circlip
11-25-2009, 05:19 AM
adapting is a good first step along what may be a long and painful road

Hmm, wonder how this fits in with some of the rest of the world DRIVING on the "Wrong" side of the road.??????

Regards Ian.

oldtiffie
11-25-2009, 05:39 AM
Its an Irish conspiracy.

The bloody "Micks" are "left-footers".

How so?

You drive on the same side of the road as the foot you use on the accelerator.

Left footer:
(don't choke - its in here! !):
http://en.wikipedia.org/wiki/List_of_religious_slurs

http://dictionary.reverso.net/english-definition/left-footer

I wonder if it has anything to do with H-D "shovel-heads"?

Of course, farmers who sit on the middle of a tractor in the middle of the road are something else - its all the same to them.

Evan
11-25-2009, 06:49 AM
US manufacturing switched to metric a long time ago. About the only corporations left that haven't are ones that don't export anything. When I started with Xerox in '75 they were just moving over to metric and by '80 all new models were metric. A few areas will lag behind because there are some standards that really are difficult and expensive to change. Building supplies tend to be in that category. The easiest to switch is food and related items and it isn't hard to make that change. A litre is about a quart and a kilo is a fat 2 lbs. A litre of water weighs a kilo and fits in a 10x10x10 cm cube. That is the sweetest part of metric, the correspondence between volume, length and weight.

wierdscience
11-25-2009, 08:57 AM
We have been converting to metric for decades,unlike most the rest of the world we didn't force the issue nor could we,nor would it matter.Somethings will remain inch for a very long time.

Look at how much has remained of the inch systems in metric countries.What size are the socket wrench drives on those metric sockets?

lazlo
11-25-2009, 09:03 AM
So, as Jergen (Sp?) says, if the USA wants to stay behind the rest of the world - and get further behind as time goes on - making it increasingly hard to change and catch up - it has a lot of soul-searching to do.

The UK and Canada still have weird hybrid systems where a lot of their measurements are still Imperial. It's amusing to read the British Model Engineer and Model Engineering Workshop articles. Most dimensions are Imperial. With Metric fasteners. Random items (usually stock plate or rod) are specifically called-out in Metric.

But like you like to say 'Tiff, there's nothing you can do to change the US, Canada and UK, so quit whining :)

Evan
11-25-2009, 10:01 AM
The UK and Canada still have weird hybrid systems where a lot of their measurements are still Imperial.

I'm not sure what you mean. We are officially metric. All weights and measures are metric including commodities such as all food, fuel, energy, timber etc. Land, weather, distances, size of houses, speedometers in vehicles, medical records, sacks of cement in kilos, cubic metres of wood, litres in a swimming pool, roofing shingles in sq metres etc, etc.

The items that aren't metric are those things that we import or export from/to the USA. Even then they must be marked in metric with some exceptions. The major area of exception is in lumber and related building materials. Saw mills here cut metric lumber as well as imperial sizes since the US isn't our only market.

You may list weights and measures in metric only or metric first followed by imperial but you may not use imperial only for labeling products unless they are imported under certain circumstances.

lazlo
11-25-2009, 11:06 AM
I'm not sure what you mean. We are officially metric. All weights and measures are metric including commodities such as all food, fuel, energy, timber etc. Land, weather, distances, size of houses, speedometers in vehicles, medical records, sacks of cement in kilos, cubic metres of wood, litres in a swimming pool, roofing shingles in sq metres etc, etc.

According to my Canadian friends who work here, food in Canada is sold in pounds and ounces. Some items are camouflaged Imperial -- like 454-gram (1 pound) tubs of butter, and 341 mL (12 ounce) beer. They cook in degrees Fahrenheit and ounces, and they refer to their height and weight in feet and inches. Real Estate is apparently still sold in square feet, and you use Imperial fasteners, NPT pipe fittings, etc.

Personally, I could care less. I grew up in Europe (Army brat) and the transition back to the 'States was no big deal. In Semiconductors, we've historically had a bizarre mixture of Imperial and Metric dimensions -- 8" wafers, and die sizes in mils, but the process nodes in micron. But we converted completely over to Metric at 65nm (circa 2006), and it was mostly changing conversion factors in our area tracking spreadsheets.

BobWarfield
11-25-2009, 11:31 AM
I've scratched my head over these conversions more than once. We had to memorize all the metric conversion constants in school (been a few years!), so that isn't too bad, but I still reach for a calculator. For fractions, I'm good to eighths in my head, but its often convenient to know it all the way down to 32's. Bottom line is I was reaching for my hand calculator quite a lot.

I wanted to make all of this much easier, and the hand calculator really didn't help me much more than doing the multiplication and division. So I thought about it and built a lot of this into my G-Wizard Machinist's Calculator:

http://www.cnccookbook.com/img/GWizard/UnitConversions.jpg

The red underlines are not part of the software, they just call out the conversion features. As you're typing in values in G-Wizard, the underlined areas are continuously updated.

For example, as you type in a decimal value, the fractions display will pop up with the appropriate fraction (in this case 3/16's) if you get within a tenth (0.0001) of the fraction. The fractions are good to 1/32's. If you click the fraction button, you get a popup list and you can select a fraction to be entered as a decimal value into the calculator.

In addition, there is continuous unit conversion going on based on the units you've chosen. By default, the calculator is set to inches and millimeters. Whatever I am typing into the main calculator display is assumed to be in inches, and is continuously updated to the corresponding millimeters on the right. There are lots of other unit conversions available (Hands to Angstroms, anyone? LOL). Want to swap? Click the "<-Use" button and the units swap places so that now you're typing mm and getting inches back.

Unit conversions even extend to angles. There are certainly degrees and radians, but the D:M:S button lets you enter degrees, minutes, and seconds and convert that to decimal degrees or radians for entry back into the calculator.

I've really enjoyed having these conversion functions handy and hadn't seen another calculator that works quite like this.

Cheers,

BW

Evan
11-25-2009, 11:32 AM
My deed shows I own 4.5 hectares of land and all the food is sold in metric here. Houses may be listed in sq ft but the legal documents will be in sq metres. Camouflaged imperial is disappearing but is usually because the product is imported from the US with new labelling. If it is made in Canada like a can of Coke it is 355ml with no imperial measure listed. Just checking the cupboard, a box of Canadian made corn starch is 500 grams and a box of graham crackers is 400 grams, no imperial listed. US made products are all sorts of weird weights like 247 grams.

Canada is fully metric but we still live in the shadow of an elephant. My grand kids have no clue what an inch or yard or mile is nor do they care.

lazlo
11-25-2009, 11:39 AM
If it is made in Canada like a can of Coke it is 355ml with no imperial measure listed.

355ml is 12 US fluid ounces :)

DR
11-25-2009, 11:44 AM
I've had a few customers who did precision sheet metal (electronic enclosures and such). Invariably these guys dimensions ed everything to 4 decimal places (probably didn't know how to reset the default dimensioning in their CAD systems).

They did their inspections with a tape measure though.....

juergenwt
11-25-2009, 03:52 PM
Thanks oldtiffie - You said it better than I could. There will always be some people who will look for rare imperial measurements used in an otherwise metric world, just to make their point to justify the use of the US customary system. Like the use of inch size tires (on the way out) or the drive square on a socket wrench, or may be some plumber in France still using inch pipes. So be it.

As far as lumber use goes - just wait till the first pre-fabs from China show up in the US housing market. You think that will never happen? Think again!

oldtiffie
11-25-2009, 05:05 PM
Originally Posted by oldtiffie
So, as Jergen (Sp?) says, if the USA wants to stay behind the rest of the world - and get further behind as time goes on - making it increasingly hard to change and catch up - it has a lot of soul-searching to do.

The UK and Canada still have weird hybrid systems where a lot of their measurements are still Imperial. It's amusing to read the British Model Engineer and Model Engineering Workshop articles. Most dimensions are Imperial. With Metric fasteners. Random items (usually stock plate or rod) are specifically called-out in Metric.

But like you like to say 'Tiff, there's nothing you can do to change the US, Canada and UK, so quit whining :)

Lazlo.

I am not whining at all - just saying it as it is.

The rest of the world is w(h)ining and d(h?)ining at the expense of the USA.

That you can't - or won't (can't?) - see it may be that you are looking over your shoulder but the rest of the world ain't there at all - is it? - its in front of you - way over on the horizon on the non-flat earth that the rest of us live in.

Perhaps the wall you built around yourself is lined with distorted mirrors - or perhaps the view is distorted but the mirrors - like your "earth" - are flat.

Just tie a stone to a bit of string, hold it steady and clear of the ground. To learn where "Up" is look at the string. "Up" is from stone to your hand. Once (if??) you understand that, I will deal with "forward" for you - and hopefully you will see a direction other than "back"(ward??).

I'd guess that even Fred Flinstone -and Barney Rubble - and certainly Wilma -will "see/get" it -and are probably metric as well. I'd bet that if Fred and Barney were looking for a good old American dinosaur, they'd have you and your address at the top of the list as it should be.

Perhaps you'd really like to eat Homer Simpson's (metric??) shorts - but I'd suggest that you wait until he gets out of them - and that they are clean!!.

lazlo
11-25-2009, 05:15 PM
I am not whining at all - just saying it as it is.

The rest of the world is w(h)ining and d(h?)ining at the expense of the USA.

So you think the US is losing sales because they're still Imperial? Can you give a couple of examples? Or even a single example?

I don't think anyone really cares what the underlying measurement system is, as long as you have a calculator handy.

So the world trades oil in 42 gallon barrels, for example, but it's pretty easy to convert to 159 liters.

oldtiffie
11-25-2009, 06:58 PM
Originally Posted by oldtiffie
I am not whining at all - just saying it as it is.

The rest of the world is w(h)ining and d(h?)ining at the expense of the USA.

So you think the US is losing sales because they're still Imperial? Can you give a couple of examples? Or even a single example?

I don't think anyone really cares what the underlying measurement system is, as long as you have a calculator handy.

So the world trades oil in 42 gallon barrels, for example, but it's pretty easy to convert to 159 liters.

First of all Lazlo, I never - or only rarely, when necessary - use "Imperial" as opposed to the normal "inch" or "British/UK" that I use in these sort/s of discussions.

If you have delusions of grandeur and of ("Imperial") "Empires" lost - or never had - go for it.

It took the Brits long enough - and they are pretty well over it - and they HAD a REAL Empire!!!

Your "imperial" suggests an "Empire" with an "Emperor". If that's so then perhaps your "Emperor" may be losing his shorts - and eating 'em - just like Homer Simpson.

http://en.wikipedia.org/wiki/Imperial

http://en.wikipedia.org/wiki/Imperialism

I note that no one - you included - has disputed Evan's statement that:

US manufacturing switched to metric a long time ago. About the only corporations left that haven't are ones that don't export anything. When I started with Xerox in '75 they were just moving over to metric and by '80 all new models were metric. A few areas will lag behind because there are some standards that really are difficult and expensive to change. Building supplies tend to be in that category. The easiest to switch is food and related items and it isn't hard to make that change. A litre is about a quart and a kilo is a fat 2 lbs. A litre of water weighs a kilo and fits in a 10x10x10 cm cube. That is the sweetest part of metric, the correspondence between volume, length and weight.

Now that infers that those hard-nosed profit-sensitive US Corporations saw it in their best interest to "Metricate" - and that is was not only cost-effective, but the "way to go" - in their own best interests.

Everyday examples in the HSM shop are the metric machines that are "hard-converted" to "inch" for the USA market. So those machines that perhaps could have - should have? - been made of/as "good old American Iron" were made "off-shore" in a metric country and modified from metric to inch. They were paid in US\$ which in turn was used to buy the raw materials (in US\$) from us in OZ.

So, it seems that metric countries selling metric goods to other metric countries - and the US - are doing reasonably well. I don't see similar levels of US "inch" product being sold to metric countries. A lot of that has to be a loss to the US because of the lack of conformation to metrics - the real international standard.

I can't see the argument or rationale' for converting from metric to inch to make something which is a hard conversion.

I've seen plenty of resistance here to using calculators -and even those that use use them unnecessarily, even if well, are at higher risks of error as well as a considerable lack or loss of efficiency and productivity. Many who shy away from calculations rely on "tables" or "Machinery's Handbook" - all (mostly) "inch".

We have plenty here who still use the "inch" (UK) system and they are pretty well catered for too. I can buy and use material or tools etc. calibrated in either system - but on a comparative measure, metric is streets ahead.

Most of us here can work in either system and can very quickly convert to and from each of them.

Metric measures are all that is taught in our schools, colleges and universities.

"Inch" etc. is pretty well past being obsolescent and is rapidly approaching being obsolete - if itnot there in large part already.

I would think that all the "foreign-owned/controlled" companies in the US are working in metrics - or if pseudo inch - in hard-converted values. I'd guess that all those very popular foreign-made (including those they make in the US) are "fully metric".

All of those "metric sales" are real or potential losses to the US economy and employment.

So far as I know, all the US/American companies working here work in metric.

You better get "Wilma" to wash Homer's shorts - I can't see you washing 'em - but I think I might see you eating 'em!!

PS.
Do you work for an American-owned or foreign-owned Company - and does that company work in "inch" or "metric"?

mochinist
11-25-2009, 07:20 PM
How did Fred Flintstones wife get dragged into washing Homer Simpsons shorts?

oldtiffie
11-25-2009, 07:24 PM
They lived (live??) in a small part of Texas.

RobbieKnobbie
11-25-2009, 07:25 PM
When I design in english, which is most of the time, I design to fractional sizes, mostly because that's what material is available in. No sense specifying a part 1.300 wide, when CRS comes in 1.250 from stock. Same thing with hole locations etc.
Any machinist or engineer worth the air he breathes should have his decimal equivelants memorized to 16ths.

A lot of the younger guys pick nominal dimensions of arbitrary numbers like 1.600 etc. Their intentions are usually good, but it's a sign of inexperience as far as I'm concerned.

As for there being no place on modern prints for fractions... Why would you send a drawing to a fab shop that shows two pieces of chanel welded to a plate 10.625" apart??? You'll never get what you're asking for and the fabricators will quickly learn to disregard your drawings.

Welded parts should (in general) always be dimensioned in fractions, and if you need a surface more precise than that, then by all means tolerance it to three decimal places - but make sure you leave material on there to be machined off, and make sure you put a machined surface mark on the print.

I occasionally get drawings that have all dimensions listed to three decimal places. I send them back; it's pure laziness on the engineer's part to leave the default decimal settings on all the dimensions the same.

Tolerances on a drawing should tell the machinist what you need to produce a functional part. Tighter tolerances make the part unnecessarily expensive and looser tolerances make the part unusable.

mochinist
11-25-2009, 07:28 PM
They lived (live??) in a small part of Texas.Weird, on my screen it says you only have 6 post and joined in 1999:confused:

oldtiffie
11-25-2009, 07:32 PM
Seems OK to me.

I regress as I get older.

wierdscience
11-25-2009, 07:44 PM
So you think the US is losing sales because they're still Imperial? Can you give a couple of examples? Or even a single example?

I don't think anyone really cares what the underlying measurement system is, as long as you have a calculator handy.

So the world trades oil in 42 gallon barrels, for example, but it's pretty easy to convert to 159 liters.

Yup and the oil that pipe flows through is inch dimension and the pipe threads and the flange dimensions and so on right down the line.

The world is full of people who think they are metric,even though they really aren't.

wierdscience
11-25-2009, 08:13 PM
Sorry wierdscience - but in the 70's when all was set to put the nation on the road to an complete and orderly transition to the metric system, Pres. Reagan pulled the biggest blunder of his life by cutting all funds for the change to metric. Today's mess is the direct result of that action. Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector. The latest report show a 35% decline in just the last 10 years.

Had a chance to research this today and you only tell half of the story.President Ford originally created the USMB (US Metricfication Board) to begin with,by 1982 it was clear that most Americans didn't give a rats backside about the metric system and the USMB was nothing more than a sick joke and a waste of money.Reagan did disband the USMB,BUT he transfered the program to the Office of Metric programs in the Dept of Commerce where it belonged to start with.

http://lamar.colostate.edu/~hillger/laws/usmb.html#disbanding

Simply blaming Reagan for "defunding" the change to metric is simply not true.That particular lie however is being posted on more than one Obama blog and several leftwing blogs who include members that do noting but bash Reagan and other conservatives.

Now enough of that.The single biggest reason for disbanding the USMB was because nobody in the American public cared save a few.

Till this day the average consumer which is 80% of the public could care less.They don't read the label in the grocery store,they SEE the size they want and grab it off the shelf.Doesn't matter one bit if it's labeled in ounces or liters.

As for the rest of us who deal with both systems,well if you can't handle both you really should chose another career:rolleyes:

At the time the USMB was dibanded there were two arguements for and against metrification.

The first was we would be able to export more if we went metric.

The second was we would import more if we went metric.

I guess we know which was right don't we?

lazlo
11-25-2009, 08:16 PM
The world is full of people who think they are metric,even though they really aren't.

Yeah, Tiffie conveniently ignores the fact that the UK has a weird mish-mash of Imperial, Metric, Whitworth, and BA. And they still measure body-weight in Stone, just to make things clearer ;)

Tiff can whine all he wants, but 100 years from now the US will still be Imperial, and the UK will still have mongrel measurement standards. And it still won't matter to anyone who has a calculator :)

Our nation, our industry and our children are paying the price. History will record that his deccission was the beginning of the decline and, as in the case of the Machine Tool Industry, the end of the once dominating US manufacturing sector.

I'll freely admit, it would have been a lot simpler for interoperability if we would have converted over in the 80's, but I don't think it makes one iota of difference to our economy. The machine tool industry crashed because no one buys manual machine tools anymore, not because we used Imperial measurements. Hell, almost all machine tools use the Imperial National Taper system. I.e., a Cat or BT spindle has 3.5" per foot taper.

Edit: sorry Darin, cross-post.

oldtiffie
11-25-2009, 08:28 PM
I think that you find that - like it or not - the UK as part of the European Union will (have to) be more and more "metric" as time goes on.

Pretty well world-wide, as the "metric only" educated kids and graduates arrive and do it their way, they will see that the rear-guard (futile) "Old and Bold" Brigade will either be tipped over the edge or fall off the twig.

The kids who will only know - or care about - metrics will just consign you to your shop or wheel-chair to just mumble away in some arcane language that they neither know nor care about.

wierdscience
11-25-2009, 08:54 PM
I think that you find that - like it or not - the UK as part of the European Union will (have to) be more and more "metric" as time goes on.

Pretty well world-wide, as the "metric only" educated kids and graduates arrive and do it their way, they will see that the rear-guard (futile) "Old and Bold" Brigade will either be tipped over the edge or fall off the twig.

The kids who will only know - or care about - metrics will just consign you to your shop or wheel-chair to just mumble away in some arcane language that they neither know nor care about.

Tiff,I have a problem with anybody or any government that wants to force change on us.
To do so ignores the benifits of natural evolution.
When we first had automobiles in the country the power source was yet undecided.It was a toss up between steam,battery or liquid fuel.

Liquid fuels won out as the evolving system sorted the best combination of features and function.The system that came forth from that process has worked remarkably well for the last 100 years or so and will continue to do so for some time.

What we have in this world,at least for machinists,weldors and engineers is an evolved system of standards based on both systems.It's accepted by and worked with by billions and somehow we manage.

The best system is one that evolves over time and not one that results from a knee jerk.

oldtiffie
11-25-2009, 09:14 PM
Thanks WS.

It will take some time and will be quicker or slower in some parts than others.

Nobody is or will or should force anything on you that you don't want.

But if you get it wrong, it will be a problem largely of your own making.

A lot of stuff that you are used to seeing and using will be here and available for quite some time yet - but it may be "hard-converted" to metric so the sizes etc. won't change -at all - as some (a lot really) is too "big" or difficult to change.

Here is an example:
http://i200.photobucket.com/albums/aa294/oldtiffie/machine_tapers/Machine-taper5.jpg

JCHannum
11-25-2009, 09:47 PM
A lot of stuff that you are used to seeing and using will be here and available for quite some time yet - but it may be "hard-converted" to metric so the sizes etc. won't change -at all - as some (a lot really) is too "big" or difficult to change.

Here is an example:
http://i200.photobucket.com/albums/aa294/oldtiffie/machine_tapers/Machine-taper5.jpg

That is a perfect example of incomplete metrification and why it will be ages before conversion is complete. The body taper is the standard 3-1/2" per foot, the balance of dimensions are metric.

oldtiffie
11-25-2009, 09:47 PM
So you think the US is losing sales because they're still Imperial? Can you give a couple of examples? Or even a single example?

I don't think anyone really cares what the underlying measurement system is, as long as you have a calculator handy.

So the world trades oil in 42 gallon barrels, for example, but it's pretty easy to convert to 159 liters.

Here's a good example:
http://americanmachinist.com/304/News/Article/False/85019/

I still have not had an answer to my query to you:

....................................
......................................

I would think that all the "foreign-owned/controlled" companies in the US are working in metrics - or if pseudo inch - in hard-converted values. I'd guess that all those very popular foreign-made (including those they make in the US) are "fully metric".

All of those "metric sales" are real or potential losses to the US economy and employment.

So far as I know, all the US/American companies working here work in metric.

You better get "Wilma" to wash Homer's shorts - I can't see you washing 'em - but I think I might see you eating 'em!!

PS.
Do you work for an American-owned or foreign-owned Company - and does that company work in "inch" or "metric"?

J Tiers
11-25-2009, 11:09 PM
That was a much used argument here until somebody pointed out that DROs don't really care what system they read out in. Our largest local job shop has mostly inch manual machines still but make most of their parts to metric specs. Things like Caterpillar heavy machinery like the backhoe I used this summer have been all metric for decades.

it's a bit difficult to thread metric with the DRO on an imperial machine.

AND, you apparently MISSED THE POINT that THE ORIGINAL ISSUE WAS 30YEARS AGO OR MORE.

DROs WERE NOT WHAT WOULD BE CALLED COMMON THEN.

That option DID NOT exist as it does now. Instead, the lead screws etc WOULD have needed to be changed, at a large cost. If it was government mandated (impossible in the USA) the cost would have been EVEN HIGHER, because there would be no alternative to compliance. You would be basically FORCED to buy the parts, at any price anyone cared to name.

oldtiffie
11-25-2009, 11:57 PM
That is a perfect example of incomplete metrification and why it will be ages before conversion is complete. The body taper is the standard 3-1/2" per foot, the balance of dimensions are metric.

Sorry Jim.

It is quite correct as it is expressed as a unit-less ratio which will apply equally well in any system of units. Note that there are no sizes or dimensions given - nor need there be - for any taper - or gradient either for that matter.

All of the 1", 3/4", 1/2, 3/8" and 1/4" square drives and sockets have an ISO/DIN standard that is "hard converted" to metric:

1" = 25.4mm

3/4" = 19.05mm

1/2" = 12.7mm

3/8" = 9.523mm

1/4" = 6.35mm

So all the traditional squares will continue to be used and available world-wide - as they are now.

There are numerous examples every-where.

The "inch", "pound", and "pint" or "gallon" are defined in the US by Act of Congress in metric terms:

NIST:
http://en.wikipedia.org/wiki/National_Institute_of_Standards_and_Technology

On February 10, 1964, the National Bureau of Standards (former name of National Institute of Standards and Technology) issued a statement that it will use the metric system:

“ Henceforth it shall be the policy of the National Bureau of Standards to use the units of the International System (SI), as adopted by the 11th General Conference of Weights and Measures (October 1960), except when the use of these units would obviously impair communication or reduce the usefulness of a report.[2]

from:
http://en.wikipedia.org/wiki/Metrication_in_the_United_States

http://en.wikipedia.org/wiki/Metric_Conversion_Act

International inch
Effective July 1, 1959, the United States and countries of the British Commonwealth defined the length of the international yard to be exactly 0.9144 meters. [1] Consequently, the international inch is defined to be equal to exactly 25.4 millimeters.

The international standard symbol for inch is in (see ISO 31-1, Annex A). In some cases, the inch is denoted by a double prime, which is often approximated by double quotes, and the foot by a prime, which is often approximated by an apostrophe.

from:
http://en.wikipedia.org/wiki/Inch

Units of length
Unit Divisions SI Equivalent
Exact relationships shown in boldface
International
1 inch (in) 25.4 mm
1 foot (ft) 12 in 0.3048 m
1 yard (yd) 3 ft 0.9144 m
1 mile (mi) 1760 yd 1.609344 km
Survey
1 link (li) 33⁄50 ft or 7.92 in 0.2011684 m
1 (survey) foot (ft) 1200⁄3937 m 0.3048006 m
1 rod (rd) 25 li or 16.5 ft 5.029210 m
1 chain (ch) 4 rd 20.11684 m
1 furlong (fur) 10 ch 201.1684 m
1 survey (or statute) mile[8] (mi) 8 fur 1.609347 km
1 league (lea) 3 mi 4.828042 km
Nautical
1 fathom (ftm) 2 yd 1.8288 m
1 cable (cb) 120 ftm or 1.091 fur 219.456 m
1 nautical mile (NM) 8.439 cb or 1.151 mi 1.852 km

The system for measuring length in the United States customary system is based on the inch, foot, yard, and mile, which are the only four customary length measurements in everyday use. Since July 1, 1959, these have been defined on the basis of 1 yard = 0.9144 meters except for some applications in surveying.[3] This definition was agreed with the UK and other Commonwealth countries, and so is often termed international measure.

When international measure was introduced in the English-speaking countries, the basic geodetic datum in North America was the North American Datum of 1927 (NAD27), which had been constructed by triangulation based on the definition of the foot in the Mendenhall Order of 1893, that is 1 foot = 1200⁄3937 meters: this definition was retained for data derived from NAD27, but renamed the U.S. survey foot to distinguish it from the international foot.[3] For most applications, the difference between the two definitions is insignificant — one international foot is exactly 0.999998 of a U.S. survey foot, for a difference of about 1⁄8 inch (3 mm) per mile — but it affects the definition of the State Plane Coordinate Systems (SPCSs), which can stretch over hundreds of miles.[9]

The NAD27 was replaced in the 1980s by the North American Datum of 1983 (NAD83), which is defined in meters. The SPCSs were also updated, but the National Geodetic Survey left the decision of which (if any) definition of the foot to use to the individual states. All SPCSs are defined in meters, but seven states also have SPCSs defined in U.S. survey feet and an eighth state in international feet: the other 42 states use only meter-based SPCSs.[9]

State legislation is also important for determining the conversion factor to be used for everyday land surveying and real estate transactions, although the difference (2 ppm) is of no practical significance given the precision of normal surveying measurements over short distances (usually much less than a mile). Twenty-four states have legislated that surveying measures should be based on the U.S. survey foot, eight have legislated that they be made on the basis of the international foot, and eighteen have not specified the conversion factor from metric units.[9]

 Units of area
Unit Divisions SI Equivalent
Exact relationships shown in boldface
1 square survey foot (sq ft or ft2) 144 square inches 0.09290341 m2
1 square chain (sq ch) or (ch2) 4356 feet2 (survey) or 16 sq rods 404.6873 m2
1 acre 43560 sq ft (survey) or 10 sq ch 4046.873 m2
1 section 640 acres or 1 sq mi (survey) 2.589998 km2
1 survey township (twp) 36 sections or 4 sq leagues 93.23993 km2

The most widely used area unit with a name unrelated to any length unit is the acre. The National Institute of Standards and Technology contends that customary area units are defined in terms of the square survey foot, not the square international foot.[8] Conversion factors are based on Astin (July 27, 1968)[10] and National Institute of Standards and Technology (2008).[11]

 Units of capacity and volume
Volume in general
Unit Divisions SI Equivalent
1 cubic inch (cu in) or (in3) 16.387064 mL[12]
1 cubic foot (cu ft) or (ft3) 1728 cu in 28.31685 L
1 cubic yard (cu yd) or (yd3) 27 cu ft 764.559 L
0.7645549 m3
1 acre foot (acre ft) 43560 cu ft
1613.333 cu yd 1.233482 ML
1233.482 m3

The cubic inch, cubic foot and cubic yard are commonly used for measuring volume. In addition, there is one group of units for measuring volumes of liquids, and one for measuring volumes of dry material.

Other than the cubic foot, cubic inch and cubic yard, these units are differently sized from the units in the Imperial system, although the names of the units are similar. Also, while the U.S. has separate systems for measuring the volumes of liquids and dry material, the Imperial system has one set of units for both.

from:
http://en.wikipedia.org/wiki/United_States_customary_units

So, even when using your "customary units" in the USA you are using units that are defined in metric units.

Carld
11-26-2009, 12:06 AM
I don't agree with some of the observations some posters have expressed. The USA didn't lose manufacturing because they didn't want to do metrics, they lost because of cost of production. The US manufacturers will make products in imperial or metric as the customer wants.

I suppose all of Europe is metric but they still make parts in imperial dimensions if that is what the customer wants. I don't think it's a matter of which is the best system as it is which system is used the most. If you learned imperial to start with then your comfortable with it. If you learned metric to start with your comfortable with that. If you have to use both your soon comfortable with both of them.

I was taught and raised with imperial so I am comfortable with that but I can use metric without trouble. The problem is my machines are imperial and for that reason I convert metric to imperial on drawings. If my machines were metric I would convert the imperial drawings to metric.

I think to much is being made out of which is easier or better when it doesn't really matter. If you think the USA is not slowly going metric you must not be living in the USA. If your living in the USA then pull your head out of the sand and look around, it's a new changing world and it's not because of Obama.

J Tiers
11-26-2009, 12:08 AM
This would probably be a good time to point out that the United States of America officially adopted the metric system over 130 years ago. AFAIK, that is BEFORE some other countries whose citizens now smugly ask when the US will "go metric".

So the USA has been "metric" for 130 years.

Those who insist on saying The USA has not adopted the metric system are either pathetically ignorant or are deliberate liars.

The difference is that unlike other countries, the USA never made the use of other units illegal. We are not that sort of place, despite the two political parties each apparently attempting to create a one-party police state.

I believe it would be found unconstitutional to make inches illegal, as well as being an extremely expensive law which would probably flush the last vestiges of industry out of the US and on to china permanently, due to the various costs of conversion.

juergenwt
11-26-2009, 01:15 AM
Wierdscience - Alaska oilpipe made in Japan. Guess why and to what dim's?
Remember all publications are being dumbed down.

dp
11-26-2009, 01:20 AM
Wierdscience - Alaska oilpipe made in Japan. Guess why and to what dim's?
Remember all publications are being dumbed down.

It was larger in diameter than any domestic vendor could produce and as it turns out, would produce. The bid was sent to Japan who also did not make a pipe that diameter but they said they would. They got the bid and everyone else started playing catchup. The vendor does not drive the market place - it was a hard lesson.

dp
11-26-2009, 01:25 AM
Since the length of the standard inch since 1959 is officially defined as a portion of a meter (24.5 mm), we're all metric now.

Evan
11-26-2009, 02:34 AM
That option DID NOT exist as it does now. Instead, the lead screws etc WOULD have needed to be changed, at a large cost. If it was government mandated (impossible in the USA) the cost would have been EVEN HIGHER, because there would be no alternative to compliance. You would be basically FORCED to buy the parts, at any price anyone cared to name.

That isn't how it worked out. The "cost of conversion" turned out to be a straw man. It was a non issue then and is totally irrelevant now. Think what you like but it doesn't change history. The switch to metric can be made at almost no incremental cost by simply replacing equipment on the usual cycle with metric equipment if it proves necessary at all.

oldtiffie
11-26-2009, 04:27 AM
With a DRO, set the distance in say inch, switch it from inch to metric on your machine or convert it to CNC/NC and use metric in your CAD system for DXF>CNC/NC code and you are off and laughing.

DRO - or in large part Servo - does not care what type or condition your lead-screw or nut is in as it is only concerned about relative movement between two machine parts

CNC/NC assumes that the lead-screw is very accurate and that there is very near zero back-lash or end-play - as I understand it.

Many CAD systems allow or provide global re-scaling and re-dimensioning as they only work in units anyway (ie no inch or mm needed!!!).

Digital tools - calipers, DRO's, height guages, micrometers, protractors etc.etc. are ready-made instant conversion tools. I am buggered if I can understand the use of calculators as stand-alone converters when all that is needed is to say set the distance etc. in "inch" if you like and then switch from inch to metric - or vice versa - job done - easily - and no calculator needed.

A bit more creative and less-limited thinking will help no end.

JCHannum
11-26-2009, 08:31 AM
Sorry Jim.

It is quite correct as it is expressed as a unit-less ratio which will apply equally well in any system of units. Note that there are no sizes or dimensions given - nor need there be - for any taper - or gradient either for that matter.

All of the 1", 3/4", 1/2, 3/8" and 1/4" square drives and sockets have an ISO/DIN standard that is "hard converted" to metric:

1" = 25.4mm

3/4" = 19.05mm

1/2" = 12.7mm

3/8" = 9.523mm

1/4" = 6.35mm

So all the traditional squares will continue to be used and available world-wide - as they are now.

There are numerous examples every-where.

So, even when using your "customary units" in the USA you are using units that are defined in metric units.

Sorry right back at you Tiff.

A dimension that is changed from one system to another does nothing to change the size of the part.

The "traditional squares" are in inch dimensions, translated to metric.

In the case of the milling machine arbors, the British standard is nothing more than the inch standard dimensions converted to metric with metric threads. They can, and have for years, interchange directly with only the need for a metric draw stud thread. These dimensions have been standard since 1953 BTW and are not the result of any legal pressure to convert but were arrived at in the name of interchangeability. The British were originally called out with BSW threads.

oldtiffie
11-26-2009, 09:19 AM
Jim.

That was my point.

Not all changes are "soft converted" to metric - ie to the nearest "preferred" number, size or value.

The same object is or can be exactly the same physical size irrespective of the defining unit/s used - inch or metric.

As the inch etc. has been defined in the USA as 25.4mm it follows that working in inches is really just working in multiples or sub-multiples of 25.4mm.

There is nothing to stop you working in inch units.

There is likewise nothing to stop the metric countries re-defining an object made under inch measurement as a "hard converted" metric(ated) standard.

We have plenty of "inch" "legacy" items and users of the redundant "inch" system here as well and all seem to be doing well enough - even after "metrication" was introduced.

Here is a potted history of how it went in Australia (OZ):
http://en.wikipedia.org/wiki/Metrication_in_Australia

http://www.measurement.gov.au/AMS/Pages/HowAustraliasmeasurementsystemworks.aspx

As I posted in a previous post, I think that the revered USA NIST is "metricated" as well, and that being so, it seems that they might (do?) "think" in "metric" and "hard-convert" to and from the USA-used inch and other imperial/preferred units.

J Tiers
11-26-2009, 10:46 AM
That isn't how it worked out. The "cost of conversion" turned out to be a straw man. It was a non issue then and is totally irrelevant now. Think what you like but it doesn't change history. The switch to metric can be made at almost no incremental cost by simply replacing equipment on the usual cycle with metric equipment if it proves necessary at all.

Bull.

Equipment is passed down through "levels" of manufacturers, or kept in service.

ALL of it would have legally had to be scrapped or upgraded AT ONE TIME if metric was made the ONLY recognized unit of measure as of some date. And the more-than-huge installed base of non-metric "stuff" would have, AND DID force the continuance of imperial units for repair parts.

It would have had to be a staged switchover, occupying many years or decades.

What a surprise............. it has been exactly that.

Evan
11-26-2009, 01:17 PM
ALL of it would have legally had to be scrapped or upgraded AT ONE TIME if metric was made the ONLY recognized unit of measure as of some date.

Your premise is false since that isn't how it was done. Changing to metric doesn't involve mandating that manufacturers only make metric parts. It has nothing to do with them. They can make whatever they like. Nobody is talking about banning other systems of measurement, only mandating the use of the metric system when measurements are to be used for purposes regulated by law, such as the sale of fuels or the advertising of quantities.

The cost issue is a strawman as I said. For example it was estimated that it would cost an enormous amount of money to change all the road signs in the country with new signs costing hundreds to many thousands of dollars each.

It turns out it was very cheap. Signs didn't need to be replaced. Instead a pair of simple peel and stick labels turns a 50 MPH speed limit sign into 80 kmh and the sign gets a cleaning in the bargain. The cost was a tiny fraction of the estimate.

J Tiers
11-26-2009, 01:51 PM
You may be familiar with the principle of "unintended consequences"......

depending on how the law was written, it might or might not do that. Defining "measuring" might be a place to start.... can you legally "measure" a metric dimension with a non-metric device (Dial on a leadscrew, etc)? is the act of using that dial legally "measuring"? is that then required to be metric-calibrated?

An unintended (maybe) consequence might easily require all sorts of stupid things. It happens with laws all the time.

We'll soon see, we have health care and cap and trade now, Congress rushing through kilopage laws which nobody actually understands.

How the details wash out on a local level will be interesting.

juergenwt
11-26-2009, 02:27 PM
It comes down to this: You can keep on working with 30 year old machines built to inch standard to save the cost of replacements and turn those machines over to the next generation, who will now be working with 50 year old machines. Still converting to produce metric parts. Your shop will than be a working museum. Just how long do you want to continue?
Or: You can bite the bullet and change.
GM found this: The final cost for the change to metric was less than 1% of their original estimate.
These overblown cost estimates for changing to metric are just a tool used to scare people away from making a decision that is needed for a modern industrial base.
The imperial/US customery system served us well for along time, but just like an old airframe can only be updated so many times before a completely new frame needs to be built, the old (imperial) system must be replaced asap.

smalltime
11-26-2009, 02:59 PM
You may be familiar with the principle of "unintended consequences"......

depending on how the law was written, it might or might not do that. Defining "measuring" might be a place to start.... can you legally "measure" a metric dimension with a non-metric device (Dial on a leadscrew, etc)? is the act of using that dial legally "measuring"? is that then required to be metric-calibrated?

An unintended (maybe) consequence might easily require all sorts of stupid things. It happens with laws all the time.

We'll soon see, we have health care and cap and trade now, Congress rushing through kilopage laws which nobody actually understands.

How the details wash out on a local level will be interesting.

I resent this statement.
We all KNOW that the government thinks of EVERYTHING before they pass a law. How can we, as stupid machinists, be expected to measure AND machine the same part. Of couse we would need to convert all our machinery to metric so we could keep it straight in our smallish heads.

You should be happy to pay more taxes to "cleanse" the planet. Hey after all man made the planet.....we can ruin it just as easy. And pay no attention to the recent ploy by the right (the dirty earthers) of releasing made up e-mails by our awesome scientitsts were they discuss manipulating data and discrediting those who don't agree.

These neanderthalls actually think the government will start throwing folks in jail for not buying insurance

Carld
11-26-2009, 03:41 PM
smalltime, the jail thing is a part of the health care bill they are trying to pass. Whether they use that part of the bill or not is up to the government.

As to the so claimed green house effect I don't believe it but everyone can believe what they want and I don't believe the stuff the hackers stole from the site is made up. Of course the owners of the site would never admit the emails and data are real.

Many scientists say we're heading for an ice age and others say we're heading for a high temp climate. I don't think there will be much carbon control so we will find out in a hundred years or so I guess but this is way of the original topic.

gmatov
11-26-2009, 10:45 PM
Ah, ****,

I've been reading and thinking "Why bust Juergen's bubble on the Metrics thing?"

I can make my way in either. Some can't, I don't know why not. All them computerized calipers are AC-DC.

I don't think that Metrics are easier than Inch measure. 1,000 miles is 1,000 miles. Half that is 500, as easy as halving 1,000 kilometers. But then you get to smaller dimensions, 1.875 inches. Halve that in your head. .9375, 15/16. Making it decimal makes the conversion less apparent. Inch and 7/8 makes it easy

20 mm as a chain size is, to me, and only because I have a drum that chain came in, is about 7/8 chain.

That we have so many who seem to have learned ONLY the Metric System in school fighting FOR it makes me wonder WHY? Is the math or the memorization too difficult for you?

If you have been a machinist that was not dialed in to a CNC from Day 1, had you ever had experience on a conventional machine, in the US, the Inch-Metric thing would never bother you.

If all you have learned is CNC and Metrics, you will have problems with Inch System. "Does not compute."

Cheers,

George

J Tiers
11-26-2009, 11:08 PM
It comes down to this: You can keep on working with 30 year old machines built to inch standard to save the cost of replacements and turn those machines over to the next generation, who will now be working with 50 year old machines. Still converting to produce metric parts. Your shop will than be a working museum. Just how long do you want to continue?
Or: You can bite the bullet and change.

Well, most companies now, faced with that sort of investment, would close the factory permanently and source from china exclusively. And they should. It is what such legislation would be intended to do, anyway.

Now, there is not one thing wrong with inch measure, other than the fact that the rest of the world uses a standard which is different by 2.54, 25.4, 39.370079.... or however you choose to express it.

"Worn out airframe"? Too many upgrades? Only silly. The problem is not anything to do with the inch standard, but rather with the fact that another standard is used in the rest of the world, and by the scientific and engineering community. The inch standard hasn't been "upgraded" at all, and doesn't need it.

Either you do metric, or not.

I don't need to bite any bullets. I happily design in either, whichever the client wants. I make parts in whichever units anyone wants. I have no problem with metric whatsoever, although I still think "hectares" are a stupid unit.

I am NOT going to scrap my personal shop machines just because you say so. I don't do that much commercial work to justify it, that's all for our prototypes.

If I chose, I could change over to metric leadscrews and dials, and go from there. But I don't need to, even with your superior understanding, knowledge, and the patronizing attitude urging me to scrap the old stuff and buy all new.

I consider the idiotic gyrations necessary to cut metric threads even on some native metric machines to be just that, idiotic. Really, 4 different gears on the thread dial? Simply a WIZARD idea, absolutely smashing, you know.

For commercial work, now most is CNC and the difference is completely without a distinction. That was NOT true back in the 60's and 70's, when CNC was not yet king. It would have been a very expensive proposition to convert every machine to metric, if that had been required (as I understand it has been elsewhere).

As it is, metric is everywhere, and if you do not see it, it is merely because you are comfortable in your superiority, and choose not to, frankly.

Have some turkey and meditate on your blessings.

Evan
11-27-2009, 01:12 AM
Well, most companies now, faced with that sort of investment, would close the factory permanently and source from china exclusively. And they should. It is what such legislation would be intended to do, anyway.
......

For commercial work, now most is CNC and the difference is completely without a distinction. That was NOT true back in the 60's and 70's, when CNC was not yet king. It would have been a very expensive proposition to convert every machine to metric, if that had been required (as I understand it has been elsewhere).

Stop throwing up that straw man. Going metric does not include any such thing as legislation that prohibits the use of the inch to make products. Nor does it include anything that would force anybody to switch to making everything in metric. That isn't what metrication is about.

You can still dimension your drawing in inches if you wish. You can still use inch based machines to make the parts although I very much doubt there are many machines left that can only work in inches.

Metrication is about what units are officially used to describe products and and anything that is prescribed in law. Even then if the product is specifically inch based then you may still use inches or whatever other unit you need to describe it.

J Tiers
11-27-2009, 09:46 AM
Don't be silly.

In the first place it all depends on how the law is written, and what the unintended consequences of the precise language are.

It also depends on the PERCEPTION of the law by the company executives. if they PERCEIVE that the law will cause them to need to re-tool, they will pull the trigger on closing and moving, because that costs less than any re-tooling . It does not have to be literally true, it only needs to be so perceived by the execs and company lawyers, who are looking for an excuse to move to a "best cost country" anyhow.

You can count on the appearance of high-priced 'compliance consultants" who would advise on the re-tooling and other actions needed to come into compliance with new laws. And of course, the higher cost of any new "special" and "compliant" equipment.

The net effect would be about what I said, because the 'straw man" you are spouting about would be actively "sold" as "reality" to businesses.

And I believe some countries have in fact outlawed the use of other units, so you may actually be literally wrong in a few cases.

Instead, we have had a slow change, which is manageable. Companies who see an advantage to being metric, have changed-over. Those who do not have not, or have not completely done so.

Metric dimensioning and whole number metric sizing has been present on millions of US parts for decades now.

let's see.... ignorant folks say the US "has not accepted metric".......

Reality is:

Metric has been accepted in the US by federal law for well over 100 years.

Companies with international sales use metric now, and many have for decades.

How does THAT get reconciled?

Yes, there is a huge installed base of equipment, houses, buildings etc which are not made in "whole number metric' dimensions, and will still need to be serviced for probably 50 years or more. So what?

"Metrication" is not just using metric units for describing sizes etc. It really includes changing all the customary sizes and volumes of materials to "whole number metric' quantities. So long as that is not done, the "metrication" is not finished.

Feh........... long enough. bye-bye , Evan

juergenwt
11-27-2009, 03:06 PM
J Tiers - If that makes you happy - so be it. I for my part are going down to my favorite watering hole and have a 12 oz beer. Than I will ask the bartender how many 12oz glasses he can get from a 1/2 barrel. Cheers!

lazlo
11-27-2009, 03:31 PM
]I for my part are going down to my favorite watering hole and have a 12 oz beer.

Or, if you're in Canada, you'll be served a 341 mL beer, and you can pride yourself on having Metricized :D

J Tiers
11-27-2009, 04:30 PM
J Tiers - If that makes you happy - so be it.

Juergen, what would make me happy would be for me to wake up and find that everyone was either metric or inch, pick ONE for all.... and that everything was dimensioned in "whole number units" of that type. I want to find that all my machines are native in that unit, und mit der Welt ist alles in Ordnung.

I really don't care which unit it is, but metric would be easier for engineering.

Evan
11-27-2009, 08:06 PM
Jerry,

Your objections are all the same as we heard before and they simply aren't valid. There is no reason to think that the US government would implement some sort of draconian ultimate metrication scheme forcing everything non metric to be scrapped. That is nothing but a scare tactic for the masses promoted by companies that sell inch based products to a captive market. They don't want to have to compete with with a world wide list of competitors. They currently have the market largely to themselves and they recognize that a switch to metric would threaten their profits because they would then have to compete on a level playing field with other manufacturers outside of the US.

The only reason that the US hasn't officially switched is because of lobbying by people that have a vested interest in not switching. It's another example of a non-tariff barrier to trade.

J Tiers
11-27-2009, 09:16 PM
Evan, the US "switched" 100+ years ago, by making metric legal for trade well before 1900.

The only effective thing that could be done now is to make imperial ILLEGAL for trade, with whatever consequences that has. I am not certain that sort of law would stand up in court, the courts have a history of letting the market decide, which is where we are now.

A half measure would be requiring metric for all suppliers to the government. Significant numbers of them are already, for military stuff. But that is only a small amount of total trade. I have a government purchasing agent's handbook to metric intended for the switchover back in the 70's.

Lobbyists? Sure. Vested interests? non-tariff trade barrier? don't make me laugh....... any vested interest was torpedoed by WalMart when they broke out with the all-china suppliers list. that trade barrier is really stopping those container ships....... Faugh............. the business owners thought it would be expensive, and fought it. probably cut their own throats doing it, too.

If imperial is not made illegal for trade, there will continue to be mixed units, because everyone who wants to switch has already switched beginning decades ago.

Myself, I like meters and mm just fine. (But hectares are still a prissy stupid unit, and saying 500g instead of a half kg for an imprecise amount is also prissy and old-maidish)

bobw53
11-27-2009, 09:20 PM
Evan, the US "switched" 100+ years ago, by making metric legal for trade well before 1900.

That makes me want to open a gas station, charge a buck less a liter than everyone else is charging for a gallon. Rich and retired in 3 months.

Evan
11-28-2009, 12:23 AM
Making metric legal for trade is not "switching". Nor is it necessary to ban imperial. The proper approach is to require that all weights and measures be given and priced in metric or metric and imperial but not just imperial.

juergenwt
11-28-2009, 12:25 AM
Back from the bar. The bartender could not answer my question about how many 12oz glasses he could get from a 1/2 barrel. Neither could the owner.
It seems like everybody agrees on metric being the way to go but many have a reason why they want to stay imperial. So pls. keep government out of my business. But when I am in deep s...,--- where is the government to help me compete? They should have seen this coming and set up guidelines to follow. In the meantime, we muddle on. Thanks for an interesting discussion.

lazlo
11-28-2009, 08:53 AM
Back from the bar. The bartender could not answer my question about how many 12oz glasses he could get from a 1/2 barrel. Neither could the owner.

One of the more useful things I learned in college is that a "1/2 Keg" or "half barrel" is 15 1/2 gallons. A "Pony Keg" is half a half keg, or 7.75 gallons.

So that makes 1/2 a barrel 1984 ounces, or 99.2 bottles of beer. "99 bottles of beer on the wall..." Or 165 12 ounce glasses, but there's no good limerick for that :)

wierdscience
11-28-2009, 09:01 AM
And even if it were metric the bartender wouldn't know how many liters in a barrels either,the public just doesn't give a rats ass.:)

lazlo
11-28-2009, 09:03 AM
And even if it were metric the bartender wouldn't know how many liters in a barrels either,the public just doesn't give a rats ass.:)

Yeah, but that's what engineering students do at the bar, while all the other students are hitting on women: they calculate the number of beers in a keg. It's amazing that engineers manage to procreate :)

wierdscience
11-28-2009, 09:11 AM
Yeah, but that's what engineering students do at the bar, while all the other students are hitting on women: they calculate the number of beers in a keg. It's amazing that engineers manage to procreate :)

Go back to my earlier statement,engineers aren't members of the general public.If an engineer can't hack SI or fractions then they really shouldn't be engineers.And I still maintain any engineer that doesn't go out of his or her way to use whole units either inch or metric should be shot:D 21.19mm blow it our your a--! :D

How they procreate is beyond me,maybe cloning?:p

J Tiers
11-28-2009, 09:14 AM
Making metric legal for trade is not "switching". Nor is it necessary to ban imperial. The proper approach is to require that all weights and measures be given and priced in metric or metric and imperial but not just imperial.

Um, if you were ever in a US grocery store, you'd find that was the case now in 99%+ of the cases. About what the compliance rate would be anyway.

Datasheet dimensions for essentially any component I look up for use in a design, electrical or mechanical, are given in both systems. It's extrememly rare to find anything else.

Won't satisfy Juergen though, and won't get the job done. HASN'T got the job done.

The "whole world" STILL KNOWS that EVERY US dimension is given to the nearest 1/128th of an inch , and in NO other system of dimensioning.

The "whole world knows" that it is ILLEGAL in the US to use metric dimensions.

YOU "know for sure" that metric is never used here, apparently.

If an engineer can't hack SI or fractions then they really shouldn't be engineers.

If an engineer CAN hack "poundals" and "slugs", etc, they should be promoted. That's the hardest possible way to go that I can think of. hate them, won't use them, refuse totally.

FRACTIONS, HOWEVER, ARE COMPLETELY RATIONAL (ducks)

Evan
11-28-2009, 09:25 AM
YOU "know for sure" that metric is never used here, apparently.

What I know for sure is that there is no legal requirement to use it for legal purposes. That is also what the world knows and until that changes the US is still officialy not metric. When the speed limit signs are in kilometres per hour the US will be officially metric.

Evan
11-28-2009, 09:28 AM
FRACTIONS, HOWEVER, ARE COMPLETELY RATIONAL (ducks)

Fractions, such as used in carpentry, are simply a six bit binary system based on the inch.

J Tiers
11-28-2009, 11:28 AM
What I know for sure is that there is no legal requirement to use it for legal purposes. That is also what the world knows and until that changes the US is still officialy not metric. When the speed limit signs are in kilometres per hour the US will be officially metric.

The moment the metric system was made legal for trade, the US was "officially metric".

Your contrary opinion on the matter is not at all important.

What you are NOW requiring is tantamount to outlawing imperial, which you have already stated is not necessary.

A complete changeover of every label and sign won't happen until imperial is outlawed, which also won't happen, and probably can't even happen legally.

but suppose it did:

Example: There are a lot of speed limit signs, since you mentioned them. A LOT of speed limit signs. Changing all of them to km/h won't be done until it is legally mandated, because of the expense. Even a sticker, or an auxiliary sign would probably cost \$25 per sign, including work crew time. No county will bother until it is mandated, and some won't then.

There are almost 6 million miles of paved roads in the US, apparently. Assuming an average of 6 signs per mile (3 each way), which is much less than exist on many roads (there is often one per block, and a mile is several blocks), we are already approaching a billion dollars for speed limit signs. Could easily be double that, depending on the number of signs.

And at the end of the day, all that billion dollars would do is satisfy Evan's personal requirement and opinion, it actually improves nothing. It's just a "public relations stunt".

Oh, sorry, I forgot, you said the changeover was basically free..... How could I possibly forget?

You need to make up your mind.

Evan
11-28-2009, 12:48 PM
Your contrary opinion on the matter is not at all important.

The rest of the world agrees with me.

What you are NOW requiring is tantamount to outlawing imperial, which you have already stated is not necessary.

No, that is not what I said or implied. When we changed over the signs were in metric with the speed also indicated in imperial underneath. They left the signs that way for perhaps 10 to 15 years while people became accustomed to the change.

A complete changeover of every label and sign won't happen until imperial is outlawed, which also won't happen, and probably can't even happen legally.

Why do you persist? It wasn't outlawed here. Making metric the legal basis of trade does not mean imperial cannot be used as a secondary system. Imperial is already legally defined by the metric system.

And at the end of the day, all that billion dollars would do is satisfy Evan's personal requirement and opinion, it actually improves nothing. It's just a "public relations stunt".

I have no stake in it but you do whether you realize it or not. The USA will continue to be hadicapped in trade with other countries as long as it is perceived that it does not conform the the world standard of weights and measures. Unfortunately from time to time there is very expensive proof that it is a problem and there is a reason to be concerned. The Mars Climate Orbiter mission cost approximately 400 million dollars, all wasted because of confusion between metric and imperial.

Oh, sorry, I forgot, you said the changeover was basically free..... How could I possibly forget?

You need to make up your mind.

You are a fool Jerry. You persist once again in attributing to me what I have not written. Why, I don't know since everyone else can read what I wrote and can see that what you write simply makes you look the fool.

BTW, 400 million dollars would buy 1 million signs at \$400 apiece. Not changing will cost far more.

Carld
11-28-2009, 01:16 PM
Personally I don't think the USA will ever outlaw the imperial system. The USA currently uses both as needed. I also don't see the USA changing the road signs to metric until everyone or most everyone quits using the imperial system in day to day lives. If the government wants to go metric they need to start teaching only metric in the schools. Maybe then in 50 years we would be all metric but again I don't see that happening, ever.

I don't think we have suffered from not being all metric, we have suffered from cost of manufacturing. Every company in the USA can and does produce in imperial and metric measurements as required by the customer. If the customers want metric they get it. If a European company had a customer that wanted imperial measurement parts I would bet the customer would get imperial parts manufactured on metric machines no less.

We're not going to drive on the left side of the road and we're not going metric and it won't cost us anything to stay the way we are.

J Tiers
11-28-2009, 07:48 PM
You are a fool Jerry. You persist once again in attributing to me what I have not written. Why, I don't know since everyone else can read what I wrote and can see that what you write simply makes you look the fool.

You Evie dearest, have now officially stepped over the line. You may now commence to shove it. We want pictures. or on second thought, maybe not.........you keep the pictures for yourself, lovie :)

The cost was a tiny fraction of the estimate.

There is your own words....... you said it was a "tiny fraction" of the estimate. Amounts to "basically free" , but apparently not to you since you are so literal minded and have such a totally non-existent sense of humor.:rolleyes:

If I am a fool, you are a bloody damn fool. Just bugger orf.

Obviously Canadian highway crews don't work like US ones. it would take 6 people and 2 trucks to do one sign in the US.... including the folks holding the caution flags and putting out the cones..... might cost more than \$25 to stick that sticker on, at union rates for the contractor :D

In any case, The use of metric is quite pervasive in the US, and anyone who seriously investigates will find that any company with pretensions to trade outside the US already does their dimensioning in metric units with or without inch conversions listed. Many of our clients request metric dimensions only, and most others accept them. Once in a while we get a request for imperial specifically, which we then do.... It is child's play to convert a drawing in Autocad, the unit is merely a dimensionless thing with only relative value.

No amount of bellyaching about how the US "isn't metric" will change the fact that there is a huge amount of metric, the fact that you can buy metric bolts at nearly any hardware store, that you can often buy metric drills and other tooling easily, that the parts and fasteners in virtually any car for the past 15 years have been metric.

of course, my made-in-Sweden vehicle has some imperial sized fasteners. but the made-in-USA truck is full of metric.

And, probably nothing but outlawing imperial will completely change every unit to a metric unit here. That is the point that Evie dearest persists in missing. I have no idea why a foreign company would not want to buy something completely metric in dimensioning from Parker Hannafin simply because Helen's diner doesn't use metric..... or the speed limit sign reads in MPH.

loose nut
11-29-2009, 09:54 AM
If you did outlaw Imperial measurement and parts, how would you fix any of the current Imperial based equipment.

You can't tell me that all the pre-Metric Imperial based equipment that is in country's like Oz and England was just thrown out, repair parts and fasteners are necessary. What would you do if they where banned? Just fold up shop?