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rotate
01-10-2010, 10:37 PM
I'm feeling like an idiot. I have box of set screws marked 3/16-24. I was looking at my tap & die set and noticed that I don't have a 3/16-24 tap, but #10-24 looked almost identical so I used that. It worked although the set screw felt a little loose.

So, what's the deal with #10-24 and 3/16-24? I feel like such a space cadet.

Don Young
01-10-2010, 10:54 PM
I don't know the exact specifications, but for common hardware they are basically the same. I think that 3/16-24 is pretty much obsolete, replaced by 10-24. The preference seems to be to use inch dimensions for 1/4" and above with machine screw numbers for smaller sizes.

Rich Carlstedt
01-10-2010, 11:35 PM
The switch from Inch to Number measuring for "small" threads produced some
wierdcases. These are generally threads less than 1/4"
In Number Screw sizes, You start with .060 as a base and it is a 0-80 thread, or 0-72 etc.
( Please note that .0625 is 1/16 , so " )" is close to that fraction benchmark)
Each sequential thread size grows by .013" and gains one digit.
A 1-72 for example is .073" and a 2-56 is .086 in the "Major Diameter" measurement.
A 10-32 is .060 PLUS .130 ( 10 x .013) or .190
Your old 3/16 thread is .1875"
The only "exact" one is 1/8-40 (ie.) as it meets a 5-40 (.060+.065) at .125 dead on.

Real confusion is with the #14 threads (.060 + .182) as its .242
So if you have a 1/4 -20 bolt, it will not fit a 14-20 hole !

Old machines and hardware still use the old standard of 100 ago

Its a lot easier, to refer to numbers than fractions.
Can you imagine doing a 5/64-72 or a similar ?
It was an attemp to make the range smaller than 1/64's
Of course it doesn't get a simpler than Metric..but I won't go there

Rich

Machinist-Guide
01-11-2010, 12:38 AM
Here is a link to a tap drill chart for number screws if you need one

Number Screw Tap Drill Chart (http://www.machinist-guide.com/tap-drill-chart-numbers.html)

mardtrp
01-11-2010, 01:03 AM
Oh the joys of playing with that outdated MONGREL system :mad:, it's about time you lot converted to the easiest system of them all, metric.:p


Mark

J Tiers
01-11-2010, 01:36 AM
Oh the joys of playing with that outdated MONGREL system :mad:, it's about time you lot converted to the easiest system of them all, metric.:p


Mark

yep, the system with 5 different possible pitches for an M12 (or is it M14) screw........

And the "standard" pitches differing depending on which country the screw is from.....

And the 4 selectable gears on the thread dial...... with the little book to tell you which to use, unless its one of the oddballs

Yah, metric isn't standardized, it's just standard....... And just as standardly effed up as "imperial".

Besides, teh 3/16 size is ancient, non-standard, and incompatible with modern ones....... It dates from before the time 130 years ago when the US officially converted to Metric.

I DO have taps and dies for 3/16, and for #12, and some other oddities

And for "standard" metric as well. European metric, not Asian.

38_Cal
01-11-2010, 02:04 AM
And then I ran across a 1/4-26 the other day. Not an ancient screw...it was a forend screw for a British BSA International Mk II Martini rifle, which started production in about 1955. None of my "special" series tap charts even mentioned that size... I was fitting a new barrel to this rifle, so I just made a new screw to match the dimensions of the original, except for it being 28 tpi. :D Easier for me, and cheaper for my customer, than trying to come up with the "proper" tap!

David

oldtiffie
01-11-2010, 02:16 AM
Originally Posted by mardtrp
Oh the joys of playing with that outdated MONGREL system , it's about time you lot converted to the easiest system of them all, metric.


Mark


yep, the system with 5 different possible pitches for an M12 (or is it M14) screw........

And the "standard" pitches differing depending on which country the screw is from.....

And the 4 selectable gears on the thread dial...... with the little book to tell you which to use, unless its one of the oddballs

Yah, metric isn't standardized, it's just standard....... And just as standardly effed up as "imperial".

Besides, teh 3/16 size is ancient, non-standard, and incompatible with modern ones....... It dates from before the time 130 years ago when the US officially converted to Metric.

I DO have taps and dies for 3/16, and for #12, and some other oddities

And for "standard" metric as well. European metric, not Asian.


Here JT.

Stop your moaning.

Be happy.

Set it to music.

Lots of tempo and even the meter/metre has fractions:
http://en.wikipedia.org/wiki/Meter_(music)

Now watch the pretty arm on the metronome .................

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

......... and you will feel sl-e--e---p----y and r-e--l---a----x and fall to s-l--ee ..........................

z-z-z-z-z
-z
-z
-z.

So have a few "zeds".

Its a lot more peaceful than you banging that "metric" drum!!!

John Stevenson
01-11-2010, 03:32 AM
yep, the system with 5 different possible pitches for an M12 screw........



Ok take the imperial equivalent of 12mm as being 1/2"

In 1/2" and I have just checked my tap list you have 12 tpi, 13, 16, 18, 20, 24, 26, 30, 32 and 40

Now ask for a 12mm bolt and 90 % of the time you will be given a 1.75 pitch bolt, the other being specials.

Out of the 10 threads I have listed for the 1/2" which one is standard ?

.

John Stevenson
01-11-2010, 03:35 AM
And then I ran across a 1/4-26 the other day. Not an ancient screw...it was a forend screw for a British BSA International Mk II Martini rifle, which started production in about 1955. None of my "special" series tap charts even mentioned that size..

David

1/4" x 26 is a standard BSF size just as you have UNC and UNF we have BSW and BSF.

Seeing as it was for a 1955 British rifle it would fall into the right size and era.

You need new tap charts that show countries other than the USA.

Neil Armstrong WAS NOT the first American to go abroad.

.

Bguns
01-11-2010, 03:42 AM
John,
Here in the Simple US, it's always the specials...

The biggest problem I run into here, is a lot of the US Metric Bolt heads are 1 mm bigger than EU metric bolts...

Fun In tight spaces.. EU is used to that, I'm sure :)

61.1 Million Brits ought to be able to tell Us 300 million plus, to get it right :)

websterz
01-11-2010, 03:57 AM
John,
Here in the Simple US, it's always the specials...

The biggest problem I run into here, is a lot of the US Metric Bolt heads are 1 mm bigger than EU metric bolts...

Fun In tight spaces.. EU is used to that, I'm sure :)

61.1 Million Brits ought to be able to tell Us 300 million plus, to get it right :)

They're still pissed that they got beat by a bunch of colonial hicks. :D

Nuttin' but love guys...just joking! :rolleyes:

John Stevenson
01-11-2010, 04:27 AM
John,
Here in the Simple US, it's always the specials...


61.1 Million Brits ought to be able to tell Us 300 million plus, to get it right :)
Now add all of Europe to the 61.1 million, then Asia, then Australia, then most of South America. :D :D

No not stirring or looking for a fight but all too often I see posts like the 1/4 x 26 and the never ending one about the Chiwanese mill / drill with the *special* 1/2" x 12 threads in the base casting when in fact they are not special but a standard, OK not UNC or UNF but those two thread standards don't cover the globe, in fact out of the USA they are obsolete.

Any decent screw thread book will list these, they are even in machinery handbook believe it or not.

.

oldtiffie
01-11-2010, 06:27 AM
John,
Here in the Simple US, it's always the specials...

The biggest problem I run into here, is a lot of the US Metric Bolt heads are 1 mm bigger than EU metric bolts...

Fun In tight spaces.. EU is used to that, I'm sure :)

61.1 Million Brits ought to be able to tell Us 300 million plus, to get it right :)

From a non-Brit but metricated country (OZ):

http://i200.photobucket.com/albums/aa294/oldtiffie/Black_book/Black_book2_P53_1.jpg

JCHannum
01-11-2010, 08:26 AM
I have thread charts for number screws, they were called ASME, up to #30. They were 14 & 16 TPI, Letter V and 25/64 tap drills respectively.

I have an acumulation of special thread taps and dies I have accumulated over the years, they do come in handy from time to time. I usedd the 5/16"-64 tap & die a while back to make an insert for a thin section where a standard thread would not have worked.

Forrest Addy
01-11-2010, 09:14 AM
Metric is for weenies.

Real men use the Imperial system of weights and measures, hunt bear with a switch, and floss their teeth with barbed wire.

J Tiers
01-11-2010, 09:26 AM
Ok take the imperial equivalent of 12mm as being 1/2"

In 1/2" and I have just checked my tap list you have 12 tpi, 13, 16, 18, 20, 24, 26, 30, 32 and 40

Now ask for a 12mm bolt and 90 % of the time you will be given a 1.75 pitch bolt, the other being specials.

Out of the 10 threads I have listed for the 1/2" which one is standard ?

.

the standard NC thread is 1/2-13 The standard NF thread is 1/2-20

All the rest are specials for particular purposes, although one may be an "NEF" or national extra fine" .... i.e. basically a special.

You can MAKE a 2"-36 thread....... doesn't make it a hardware store standard.. it isn;t the US threads in question,.... we know they have oddities from the last 150 years + of industrial activity.

It's the holy standard METRIC, which claims to be so standard, but turns out to be just as messed up as any other system in reality.

John Stevenson
01-11-2010, 03:47 PM
the standard NC thread is 1/2-13 The standard NF thread is 1/2-20

So two standards ?
Send the lad out to the hardware shop for a standard 1/2" bolt, what will he come back with ?

Outside of the US no one uses UNF / UNC any more. At one time the Auto industry in the UK used these as a lot of companies were American based but with recent sell off's Japan and Europe have taken over as owners and they use metric.



It's the holy standard METRIC, which claims to be so standard, but turns out to be just as messed up as any other system in reality.

Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.

.

If he wants any other pitch he'll have to ask for it.

psomero
01-11-2010, 03:56 PM
So two standards ?
Send the lad out to the hardware shop for a standard 1/2" bolt, what will he come back with ?

Outside of the US no one uses UNF / UNC any more. At one time the Auto industry in the UK used these as a lot of companies were American based but with recent sell off's Japan and Europe have taken over as owners and they use metric.



Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.

.

If he wants any other pitch he'll have to ask for it.




when you go to the hardware store, anybody worth a damn will know to ask you "coarse or fine thread pitch?" when you ask for that 1/2" bolt...

john hobdeclipe
01-11-2010, 03:58 PM
Just to add a bit of interest to our lives...the tapped holes in those aluminum 19" server/relay/telecom racks full of high tech equipment are usually#12-24.

tyrone shewlaces
01-11-2010, 04:45 PM
So two standards ?
No. One standard with fine and course pitch. Metric has fine and course as well. Metric and imperial both also offer "special" threads but that's just stupid in most cases and we won't go there. No advantage of one over the other. The problem is that switching to metric takes tons of cash for tooling, so demanding that the manufacturing behemoth the US once was to change to metric because some French wussy, bottle-glasses Beaker scientist could then just move the decimal instead of having to remember a conversion factor just wasn't going to happen.



Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.
Yea and over here he'll bring you a 1/2-13. If you want fine pitch, then you'll have to send him back a second time.

I don't see why anyone thinks there's such an advantage to metric. The metric bolt notation even looks clumsy to me. Ever screw up and read 1.25 to be 1.75 for a pitch and vise-versa? That's the problem with metric. You want to be lazy and just move a decimal place? Fine. Now you have decimals in everything because you aren't allowed to just divide something up anymore. Especially if it's thirds or something. Oh God - Blasphemy! 1/3rd of a centimeter? Unheard of! Why? (I think the American engineers picked 13 for the pitch of a 1/2" bolt just as a jab to the metric fans. "1/13 of an inch? Is that even allowed?" hehe.)
I think people who love metric are the same type who hate fractions or something. US units are good for learning fractions. Units are supposed to be something divided up to begin with right? Whomever limited the divisions to only 10 was just short-sighted. Why not be able to divide something into whatever unit is the most useful instead of arbitrarily picking 10? THAT'S right - I called metric "arbitrary" and I meant it.

If a guy is not good with numbers, he's not going to be much good in either system. He'll be able to blame the "other" system though, so he's got that going for him.

The world will NEVER settle on a single standard I don't think. Unless metric could include the two most universal units in the universe, it will never take off. I'm speaking, of course, about the units of HH and FF. These are used more than any other unit in history and their intuitive relationship to all things is apparently undeniable. It's the newscasters' standard measure and the abbreviations of course stand for Human Hair and Football Field.

This silly "metric system" thing doesn't stand a chance.

SDL
01-11-2010, 05:00 PM
They're still pissed that they got beat by a bunch of colonial hicks.

NO Were pissed you needed the help of the French:D:D

Steve Larner

spope14
01-11-2010, 05:12 PM
Did anyone mention that 3/16-24 is a very close 10-24 thread? Same thing pretty much except for the major diameter for the 10-24 on an OD thread is .1890 for the high limit class 2, Machinery's handbook ed. 24. The only real change being about .0025 on the OD thread allowance, the 3/16 being a bit smaller by that much for the high limit.. Found a 3/16-24 in a very old machinist textbook in my library finally. I would wonder about the loseness, the 10-24 tap may be an H3 type? The H shows your "oversize" cut allowance.

S_J_H
01-11-2010, 05:13 PM
I think it just boils down to what you were brought up using. I have used imperial since I was a kid so my mind naturally works in imperial units MUCH easier. I can instantly envision a 1/2-13tpi bolt in my head like a picture. But if I try and envision a 12mm 1.75 pitch I have trouble.
Given a lathe that cuts all threads, I always will select a imperial thread for my projects just because I get all warm and fuzzy and stay in my comfort zone.

Any real Hardware store in the U.S. has a decent bolt section with coarse and fine selections for imperial. Most will have a good selection of metric fasteners as well.
Again, If I am cobbling up something and need fasteners for the project I always choose imperial. It has nothing to do with which is better, just sticking with what I know best.

Old dog, old tricks right?

Steve

John Stevenson
01-11-2010, 05:15 PM
The problem is that switching to metric takes tons of cash for tooling, so demanding that the manufacturing behemoth the US once was to change to metric because some French wussy, bottle-glasses Beaker scientist could then just move the decimal instead of having to remember a conversion factor just wasn't going to happen.

.


That sums it up "the manufacturing behemoth the US once was"

You have no control over imports.

Why not insist that all Grizzly machines ship in with UN threads ?

Will the new South Bend have UN series threads?

BTW I'm not saying that one system is better than another all I'm saying is that you need to look around and see what others are doing.
Who else uses the number thread system for threads below 1/4" in the world ?

You are buying in imports designed in metric but who wants to buy imperial exports in todays multi national world ?

Look at this.

http://www.ctctools.biz/servlet/the-Tool-%26-Work-Holding-cln-ER-Collet-Chucks/searchpath/18225/start/73/total/82/Categories

There has been enough demand for them to now make R8 tapers with M12 drawbar threads instead of 7/16" UNF because many countries don't have a clue what UNF is.

.

JCHannum
01-11-2010, 05:49 PM
There has been enough demand for them to now make R8 tapers with M12 drawbar threads instead of 7/16" UNF because many countries don't have a clue what UNF is.

No big deal, NMTB taper tooling has been available with Imperial and Metric threads for years. It is a matter of use.

I will make a WAG that 9 out of 10 consumers in any country neither know or care what threads a given piece of equipment uses. It is only a very few, such as ourselves, who even know what the various threads are. To most, they are big or small or maybe medium sized.

A 9/16" bolt uses a 9/16" wrench right?

Timleech
01-11-2010, 05:59 PM
A 9/16" bolt uses a 9/16" wrench right?

It does if it's Whitworth :D

Tim

John Stevenson
01-11-2010, 06:20 PM
Ssshhh Tim,
Don't let on that old Joseph who set the first standards up before American was even found and used 55 degrees with rounded roots and flanks is still the strongest thread form to date.

.

Uncle O
01-11-2010, 06:24 PM
Really , we just don't care.

Peter N
01-11-2010, 06:30 PM
Really , we just don't care.

Of course you do, otherwise you wouldn't have posted that. :D

oldtiffie
01-11-2010, 06:48 PM
It seems that as a general statement of what seems to be case here, that those of us in "metric" countries (most who "grew up" with "imperial" and adopted and adapted to "metric") accept and use and work in and with "imperial" every day of the week.

Its almost if as we are bi-lingual in that sense as we are quite comfortable working with both systems.

Many in the US seem to be "in denial" that metric even exists let alone is used and useful by anyone (else) anywhere (else).

The US is quite free and within its rights to "stay imperial" and most of the metric world is quite prepared to let it - as it should.

I have quite a few tools that are "inch" - dial indicators are good case in point - that are calibrated to 0.0005" ("five tenths" or "half a thou"). As 0.01mm is precisely 0.0003937" is is more than good enough to say the 0.01mm = 0.0004".

It is easy to see by eye - without any conversion that "half a thou" (0.0005" = 1 1/4 x 0.01 = 1.25 x 0.01 ~ 0.0125mm - or put another way 0.01mm ~ 0.0004 ~ 4/5 x the 0.0005" calibration.

I can work just as well using metric indicators and converting to "inch".

The best and ideal way of course is to use digital tools (micrometers, DRO's, calipers etc., set them to your dimension and system of choice and then press the "in/mm" conversion button and there you are - instant conversion.

My bet is that the trade stockists in the metric countries have a better "inch" range of product than the "inch" country (USA) has of "metric" stock.

jdunmyer
01-11-2010, 06:49 PM
I, too am beginning to love the standardization of Metric. Sunday, I made a new jet for a snowmobile carburator. First thing was to figure out what thread it was, assuming metric, as it's a Yamaha from Japan. Hmmm... looks to be about 5mm. Check my Metric tap & die set to see what thread it might be and find....let's see....can it be? Yes, I have FOUR choices in a 5mm size: .75, .8, .9, and 1.00 pitch!

God only knows how many different 5mm threads there'd be if Metric wasn't so standardized.

tyrone shewlaces
01-11-2010, 06:51 PM
Ssshhh Tim,
Don't let on that old Joseph who set the first standards up before American was even found and used 55 degrees with rounded roots and flanks is still the strongest thread form to date.somewher

Now see there ya go braggerin' er sumthin'.
So 55 degress is stronger and the rounded root & flanks is stronger. No argument from me there. But is 55 the magic number? Maybe 54-1/2 is even stronger and 55 degrees is just a lazy cop-out.
So going 60 degrees is a lazy cop-out to begin with. Those rounded root and flanks is what you get after a bit of production dulls the tool anyway, so no need to spec it. Management cost-savings. Cop-out.
A Whitworth form of some size will fit somewhere inside the cross section of a 60-degree V after all. It's in there somewhere.
Technically 60 degrees is 1/3 of an about-face. It's that fraction thing again I think. We like fractions here.

In actuality, just making a bolt bigger than needed will do fine, and does, unless weight is an issue. So do they use Whitworth in Aerospace? Probably should. Probably don't.
60 degrees is metric and metric is all scientific and aerospace is all scientific too. Probably just metric fasteners. Another cop-out.

But as my pappy always said - "If it weren't fer half-assed, nothing would ever get done."

Uncle O
01-11-2010, 07:10 PM
It seems that as a general statement of what seems to be case here, that those of us in "metric" countries (most who "grew up" with "imperial" and adopted and adapted to "metric") accept and use and work in and with "imperial" every day of the week.

Its almost if as we are bi-lingual in that sense as we are quite comfortable working with both systems.

Many in the US seem to be "in denial" that metric even exists let alone is used and useful by anyone (else) anywhere (else).

The US is quite free and within its rights to "stay imperial" and most of the metric world is quite prepared to let it - as it should.

I have quite a few tools that are "inch" - dial indicators are good case in point - that are calibrated to 0.0005" ("five tenths" or "half a thou"). As 0.01mm is precisely 0.0003937" is is more than good enough to say the 0.01mm = 0.0004".

It is easy to see by eye - without any conversion that "half a thou" (0.0005" = 1 1/4 x 0.01 = 1.25 x 0.01 ~ 0.0125mm - or put another way 0.01mm ~ 0.0004 ~ 4/5 x the 0.0005" calibration.

I can work just as well using metric indicators and converting to "inch".

The best and ideal way of course is to use digital tools (micrometers, DRO's, calipers etc., set them to your dimension and system of choice and then press the "in/mm" conversion button and there you are - instant conversion.

My bet is that the trade stockists in the metric countries have a better "inch" range of product than the "inch" country (USA) has of "metric" stock.


This entire post is laughable....who said we don't/can't use both Imp/metric
daily ? It is nothing to convert one to the other or switch the machinery over to read one or the other. What ever gave you the idea that you were so special ?

oldtiffie
01-11-2010, 07:22 PM
OK - you've convinced me - now convince the denialist anti-metric brigade who don't/won't/can't see any use for or use metric at all.

I didn't claim to be special at all - just an ordinary one of a large group of the great unwashed in metricated countries and industries.

As I said, it seems to me that the metric people are more acceptable/adoptive of/to inch than the "inch" users are of metric.

Rich Carlstedt
01-11-2010, 07:38 PM
I blame the inventor of the screw cutting lathe, Mr Henry Maudslay ( A Hero in my book !)

Had he left the dam change gears out, We all would be cutting 4 threads per inch, no matter what diameter the shaft/shank was..!

Thats where it all started..
And as to who is right ..I use all threads..I have BA (47 1/2 deg !) ,ME (55 deg) ,NC,NF,NEF,metric (all 60 deg) and a few Whitworth (55 deg) in my home shop.
Most resistance to metrics in the USA is not by manufacturers ...its a consumer issue. The world market place has forced them to respond years ago
Our Autos here have been metric for 20 years.
Mechanics I know work with both with ease , as do I
The machines we made at work were of either fastener ..whatever the customer desired
I think home shop folks like we have here, resist the metrics becauuse of the cost to upgrade their inventory and tools....no small change.
Is there conflicts in metric 'rules" ?..... absolutely !

but consider this:
I would say that since Mr Whitworth ( a Prime Apprentice of Maudslay)started the practice of standardization of threads, the only real thread is his..... But our friends in Britain deserted their great hero and went elsewhere..so their knickers aren't clean either

Lets all return to Whitworth !
Any thread not a Witworth is a devient !
Oh, I almost forgot..he used inch dimensions..

Rich

JoeCB
01-11-2010, 07:49 PM
Back to the topic of old standard threads... The old American standard threads are sometimes encountered when working on period machines. Outboard motors from as late as the 1920's sometimes used # 14-20 (.242) and #16 -20 (.268) screws. Since these are often encountered in aluminum, sometimes even with aluminum screws it's not umcommon for a newbe to get in trouble trying to use modern 1/4 -20 hardware and tools.
Joe B

Blueskys
01-11-2010, 08:00 PM
So, what's the deal with #10-24 and 3/16-24? I feel like such a space cadet.

If that was the worst that happened to me today it would be my best day
since I was about 4 years old.

I would tell no one, burn the box and reciept and pretend they were 10-24s.
And maybe use a little locktite.

tyrone shewlaces
01-11-2010, 08:04 PM
As I said, it seems to me that the metric people are more acceptable/adoptive of/to inch than the "inch" users are of metric.
ah HA! That's true. There's the proof that imperial makes more sense. Imperial users don't like the metric with all it's different useless units, all being 1/10 of each other, buggering up the system and being all uppity.
Metric users on the other hand, secretly yearn to dip their toe into the refreshing pool of imperial-ity.

Ahhh yesss.
All I need now is a martini.

Don't be too jealous though. It's not all hams & plaques. We do have to put up with the occasional metric blueprint now & then. It's just annoying.

kc5ezc
01-11-2010, 08:08 PM
Yep, 12x24. I tried to get them at Fastenal, but the counter guy said they we not allowed to keep any #12 screws. Had to go to Home Depot.

oldtiffie
01-11-2010, 08:17 PM
I'm feeling like an idiot. I have box of set screws marked 3/16-24. I was looking at my tap & die set and noticed that I don't have a 3/16-24 tap, but #10-24 looked almost identical so I used that. It worked although the set screw felt a little loose.

So, what's the deal with #10-24 and 3/16-24? I feel like such a space cadet.

Rotate.

This should go a fair bit of the way to helping you.

Note that as this is an OZ book and that we are metricated that the tapping and clearance holes sizes are (in) metric (mm).

Just divide by 25.4 (or multiply by 0.04) and you will have a conversion to inch.

http://i200.photobucket.com/albums/aa294/oldtiffie/Black_book/Black_book2_P32-33_1.jpg

J Tiers
01-11-2010, 08:37 PM
Actually, I like MM, I just like thousandths better than 0.01 MM increments for small stuff..... You can measure thousandths by hand, and they are small enough.

The 0.01 MM is in the tenths, actually 10 microns, too fine for good shop hand measurements, as we often discuss right here. On the other hand, 0.1mm is awfully coarse...... basically 4 thous.

MM are good for hand-sized measurements. Metres are good for large measurements like ships.

Where is the unit for people-size measurements? Metres are too big, you need too many decimal places. MM get ridiculous as you get into thousands of them.

"Oh, it's about 1.21 metres"............ that's just silly. but "it's about 4 feet" is perfect.

That is the good thing about inches... they are "right sized" for people-size stuff. Even feet are a good unit for people-sized stuff. Metres are not, way too big.

"Meters" might be, they tend to be about 2" or 3" diameter, and so they are a useful sized unit....... but you might have to call them out as air, steam, or volts. And carrying them is an issue.

spope14
01-11-2010, 09:27 PM
Bottom line here is that you have to work with both these days if you are in any machine shop, dealing with repairing any item, and even in the home shop. Many cabinet wood applications went to a 35mm basis years back as well.

I apprenticed and went to college during the great metric change over, then falter, had to know both to design and produce with linear measurement in precision applications.

This all said, I have most of my fasteners and drill tools in english because this is what I pick up at the yard sales. Any more though, when buying met fasteners for a specific repair job, I pick up several to get supplies up in that regard.

oldtiffie
01-11-2010, 09:29 PM
Actually, I like MM, I just like thousandths better than 0.01 MM increments for small stuff..... You can measure thousandths by hand, and they are small enough.

The 0.01 MM is in the tenths, actually 10 microns, too fine for good shop hand measurements, as we often discuss right here. On the other hand, 0.1mm is awfully coarse...... basically 4 thous.

MM are good for hand-sized measurements. Metres are good for large measurements like ships.

Where is the unit for people-size measurements? Metres are too big, you need too many decimal places. MM get ridiculous as you get into thousands of them.

"Oh, it's about 1.21 metres"............ that's just silly. but "it's about 4 feet" is perfect.

That is the good thing about inches... they are "right sized" for people-size stuff. Even feet are a good unit for people-sized stuff. Metres are not, way too big.

"Meters" might be, they tend to be about 2" or 3" diameter, and so they are a useful sized unit....... but you might have to call them out as air, steam, or volts. And carrying them is an issue.

Well - let's see.


The 0.01 MM is in the tenths, actually 10 microns, too fine for good shop hand measurements, as we often discuss right here. On the other hand, 0.1mm is awfully coarse...... basically 4 thous.
0.01mm ~ 0.0004" ("four tenths") - just under 0.0005" ("half a thou") and well with the reach and capability of most HSM-ers and 0.10mm ~ 0.004" ("four thou") - also easily related to.

The biggest PITA with metrics are the bloody drills as they have increments of 0.50mm (~ 0.020" ie "20 thou") where-as I prefer the "inch" sets with increments of 1/64" (= 0.0156" ~ 0.016" - ie "16 thou") as it "fits in" better for me with the smaller "jumps" or "steps". I use "inch" "number" and "letter" drills as well - so "inch" is a clear "winner" in that regard.

I suppose that we "metricated" people were pretty well forced or obliged to "go metric" because of "pressure" and "circumstance" and perhaps if we weren't a lot of us would have "stayed inch" as seems to be the case in the US.

But having said that and having had to "make the break" from our "inch" "comfort zone", I am glad we had to do it at the time we did.

Having broached the subject of metric and inch drills and conversions etc., I felt obliged to post a table that pretty well sorts it out.

I hope it helps:
http://i200.photobucket.com/albums/aa294/oldtiffie/Black_book/Black_book1_P4-5_1.jpg

whitis
01-11-2010, 09:32 PM
So, what's the deal with #10-24 and 3/16-24? I feel like such a space cadet.

3/16 is 187.5mils and #10 is 190mils.

In days of yore, there were way too many "standard" thread sizes (not to mention non-standard ones). There were the gauge (machine screw) sizes and the fractional sizes. It was decided over time to throw out the fractional sizes below 1/4" and throw out the gauge sizes above #12 as well as most of the odd sizes. In 1920, machine screw sizes went up to #30, which was 450mils in diameter; even back then, the National Screw Thread Commission recommended that sizes above #12 not be used. And SAE only recognized fractional sizes above 1/4". The Unified Thread Standard adopted in 1949 after all the interoperability problems in world war II, excludes fractional sizes below 1/4" and gauge sizes over #12. Even in 1864, it appears that William Sellers' United States Screw Thread Standard dealt with fractional sizes only down to 1/4". Also, the preferred thread pitch for many sizes changed over the years. So, it seems that even a century ago 3/16-24 was a bastard size.

Imagine all the combinations of diameter, thread form, pitch, length, fastener type, etc. Some varieties were killed off or made non-prefered. Whitworth and straight V threads were harder to make than Sellers, UNC is more common that UNF, odd numbered gauge sizes are rare, etc.

And metric may eventually kill off the imperial sizes.

John Stevenson
01-12-2010, 04:38 AM
Where is the unit for people-size measurements? Metres are too big, you need too many decimal places. MM get ridiculous as you get into thousands of them.

"Oh, it's about 1.21 metres"............ that's just silly. but "it's about 4 feet" is perfect.

.

Not hard once you get used to it like everything.

Talking of thousands we use Tonnes here, metric tonnes, 1,000 Kg to a ton.
So when we talk of trucks we say 42 tonnes gross weight.

You say 92,000 pounds or whatever .

That's thousands of them isn't and silly.

.

oldtiffie
01-12-2010, 04:58 AM
It gets better John as the difference between a "standard" ("long") USA/"inch"/"imperial" ton and a metric tonne is less than 2%, so the "1,000's of pounds" use and argument for it fall flat for every-day use as 42 tonne sounds better.


Conversions
One tonne is equivalent to:

One megagram (exactly);
This is the official SI term, but not generally used in industry, in shipping nor colloquially
1000⁄0.45359237 pounds (exactly by definition), giving approximately
2205 lb (to four significant digits)

98.42% of a long ton

One long ton (2,240 lb) is 101.605% of a tonne


110.23% of a short ton

One short ton (2,000 lb) is 90.72% of a tonne

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

darryl
01-12-2010, 05:54 AM
So what about beer- now we have a 'sleeve'- how much friggin beer is that, anyway? I always thought a sleeve was something you wiped your nose on.

'yeah, I'll have a sleeve of Rickards please' 'will that be a short sleeve or a long one?- sir'

Uh, lessee- 894 millilitres- JUST BRING ME THE DAMN KEG- %#$&^*!

tyrone shewlaces
01-12-2010, 01:15 PM
Not hard once you get used to it like everything.

Talking of thousands we use Tonnes here, metric tonnes, 1,000 Kg to a ton.
So when we talk of trucks we say 42 tonnes gross weight.

You say 92,000 pounds or whatever .

That's thousands of them isn't and silly.

.

No. For 92,000 pounds we'd say 46 tons.

Tons have been around longer than tonnes haven't they? Why not say 42 teragrams? Why add to the confusion in two ways, by using a word that sounds exactly like the imperial unit and appears very close, and interjecting a new unit into the system that already has a unit name for that?
It can't be an abbreviation of teragram, because (at least over here) you never hear someone just say "tonne", they have to say "metric tonne" - not a shortcut. Should have just stuck with teragram.
Did someone maliciously plot it out and add two letters to come up with that tonne unit in an effort to intentionally confuse, or was it someone at the opposite end of the spectrum who was just short-sighted? Now we just have to live with it.
I guess the good thing about metric is that instead of 150 separate systems of measurement throughout the globe, now we only have a handful. Once we in the US finally fall completely apart (we're on our way there in a hurry) and have no better reason than stubbornness to adopt, I guess we'll then finally be forced to do so.

loose nut
01-12-2010, 04:35 PM
Outside of the US no one uses UNF / UNC any more.



We still use them in Canada, it's what you will get at any local hardware store, just as some Brits still use BSW, BSF and BA systems and many other Metric countries still use obsolete (non-ISO systems) Metric screw systems. As for the Whitworth system, if you read up on him, he just went around to the main shops of the day and averaged out the different screw standards each of them was using and it came out to 55 Deg. If it really is stronger then the 60 Deg thread form of Imp. and Metric it was a bit of luck not genius, the genius was selling standardized threading kits and making $#!+ loads of money.

There is only one thing wrong with the metric screw system, it was designed by a bunch of syphilitic bureaucrats whose brains had started to melt and not machinists. It was made to be neat and not to fill the needs of the countries with existing metric based screw system. If you don't believe me, why does metric notation use the comma as a separator instead of the period, it's called a decimal POINT not a decimal comma. Some 'crat came up with that.

There isn't any world wide standardization in
language,
money,
religion,
calenders,
direction of writing,
which side of the road we drive on,
voltages,
TV signals,
train track sizes,
etc. etc. etc. It goes on and on, get the point.

We don't standardize anything else why should we standardize measurement.

The only universally applied standard that works is Time.

John Garner
01-12-2010, 04:54 PM
oldtiffie and all the rest of you --

I find it particularly ironic that a text intended to describe in great detail the geometry of some particular threadform gets the name of the threadform wrong.

The case in point? The text shown in Post 41 of this Thread.

The basic geometry -- sixty degree angle between flanks measured in a plane containing the axis of the screwthread, with a 1/8 Pitch flat at the Major Diameter and a 1/4 Pitch flat at the Minor Diameter -- is that of the Unified screwthread, which was developed jointly by the U.S., Canadian, and British in 1949 to preclude recurrence of the WWII logistics problems created by the differences between U.S. Standard and British Standard screwthreads and fasteners.

In standardizing their newly-developed Unified threadform, the U.S., Canadian, and British authorities developed two series of Diameter and Pitch pairings, one relatively coarser than the other. The coarser of the two series was termed the Unified Coarse series, the finer was termed the Unified Fine series.

The abbreviation for the Unified Coarse series of standard screwthreads is UNC, that for the Unified Fine series of standard screwthreads is UNF.

The U.S. Government made the Unified threadform the official standard U.S. threadform, replacing the earlier standard, which was designed and had been proposed as the U.S. Standard threadform by William Sellers in 1864.

Over its lifetime, that earlier U.S. Standard threadform had collected a variety of different names, including 1) Sellers, 2) U.S. Standard, and 3) American National. Like the later Unified threadform, the Sellers / U.S. Standard / American National was standardized in two series of Diameter - Pitch combinations, a Coarse series and a Fine series.

In common U.S. use, the two series were termed [American] National Coarse and [American] National Fine, abbreviated NC and NF, respectively.

Despite oldtiffie's textbook -- and many other textbooks -- there is no "Unified National" screwthread standard. "Unified" is one standard threadform, "National" is another.

Then, for what it's worth . . . in 1959, a full decade after the British, Canadian, and U.S. jointly developed the Unified threadform for their common use, the ISO incorporated the geometry of the Unified threadform into their new screwthread standard, which they named ISO Metric. A number of European nations -- including France, Germany, Switzerland, and Italy -- officially replaced their earlier (and largely NOT interchangeable) national standard threadforms with the ISO Metric standard.

Because the fundamental geometry of the ISO Metric threadform exactly matches that of the older Unified threadform, it can be fairly argued that the ISO Metric standard is simply a special case of the Unified standard.

John

loose nut
01-12-2010, 05:15 PM
oldtiffie and all the rest of you --

Because the fundamental geometry of the ISO Metric threadform exactly matches that of the older Unified threadform, it can be fairly argued that the ISO Metric standard is simply a special case of the Unified standard.

John

Oh boy, are you going to get it now:D :D :D

John Stevenson
01-15-2010, 07:03 PM
No. For 92,000 pounds we'd say 46 tons.



From a current post on Heavy hauling pic's by Dockrat there is a link to another move where it states;-

Check out this load. They are hauling a coker that was built in Edmonton and hauling it to Fort McMurray. There is one truck pulling and two pushing. Total weight is 1,757,688 lbs. Have a good look at the bridge as it goes over.

Read more: http://www.dieselbombers.com/show-tell/21694-fort-mcmurray-bridge-bender.html#ixzz0cjEm441D

Some one else post a pic about a large move within the last month all in pounds, can anyone visualise 1,757,688 lbs ?

.

loose nut
01-15-2010, 09:29 PM
Can anyone visualize 798949 KG's.

spope14
01-15-2010, 10:35 PM
3.5 metric tons is what I tell my students when they ask something. Sounds pretty large.

J Tiers
01-15-2010, 11:02 PM
Well - let's see.


0.01mm ~ 0.0004" ("four tenths") - just under 0.0005" ("half a thou") and well with the reach and capability of most HSM-ers and 0.10mm ~ 0.004" ("four thou") - also easily related to.



it's within reach, but typically isn't done much.... a couple thou is common, 5 thou is getting 'loose", and under a thou is "pretty tight".

but, 4 tenths IS 10 microns..... getting to "Evan territory" there...... Normally for that sort of measurement you folks all start talking about unrealistic tolerances for the home shop, and thermal effects etc...... Why the silence now?

it may be 40% of a thou, but its more than twice as fine a measurement...... well into thermal error territory. Normally a tolerance reserved for bearing fits etc.

It's all in what you are used to, you can measure with anything...

John S.....

Of course you CAN use any unit, and some do, often to get a bigger and more impressive number....

But to have no intermediate measuring unit between two that are a factor of 1000 apart , is un-handy.

When that 'gap" is right in the area of 'people-sized" things, where decent accuracy is useful, it's more un-handy.

it would be better to have a unit about a half metre in length.

With all its faults, and I won't deny them, the inch/foot/yard series gives a number of useful measurement units in the "people-size" area. And all of them are easily related, all just really common names for multiples of inches. A foot could as easily been 10 inches...... in which case we might not be having this conversation.

metric WOULD have a reasonable sized unit, IF the "decimeter" had not been "deprecated"...... a decimeter would be about 4", and would be a useful subdivision......

And, by simply messing with the decimal places, you CAN get there..... "about 1.3 metre"......

if you are satisfied to "pollute" metric with fractions, you can do better...... "about a half metre"......... "about 2/3 metre"........ I like to do that just to mess with the tight decimalized minds of the metric advocates....... It's like asking a symphony violin player to improvise........ you are never quite sure if you will see a real case of human spontaneous combustion as a result.

People have odd ideas of the US..... I sent a fellow in europe a picture of some machine part or another, and included a metre stick in the picture for a size reference. He was astounded that I would possess such a thing. But they aren't that uncommon.

tyrone shewlaces
01-16-2010, 11:47 AM
J Tiers
A foot could have been 10 inches rather than 12, but it was extremely likely created on purpose to have 12. For the common man (you know, the guy who makes and/or grows things and takes them to market to sell, etc.) base 10 doesn't work out as well. This is even more true the less literate folks are. It seems a small thing, but the simple act of dividing things up is a big deal in the concrete world, so 12 rises up to be more functional than 10. It can be divided by 2,3,4 and 6 and can be divided in half twice before you get into fractions. 10 can be divided by 2 and 5 and you're into fractional amounts right away.
Having said that, dividing by 2 and 5 might be handy enough. If the metric pushers of yore would have come up with a prefix or suffix for 1/2 and 1/5 of a unit (like meterak and meterpoo for example), it may have been easier to sell. Still not as good as base 12, but a little more serviceable for the common man.
I still say the base 10 is great for figuring things on paper, but in the physical world it is too far down on the list as choices go.
Metric - Shmetric.
Actually the best thing would have been for the world to just pick one and run with it. I personally wouldn't care much. Well I do now since I'm better than half a life through the units that I have been dealing with so far, but starting out young with a single standard would have been kinda handy. A "standard" isn't a standard when you have more than one of them. Metric was a good effort. They tried but the spaghetti didn't stick to the wall.

mardtrp
01-16-2010, 03:23 PM
Wow, has this thread gone way of topic or what ? :eek:

It seems that this argument about imperial and metric will be around for many years to come and the main 'stayers' for imperial measurment are/is the 'dumb':p Yanks.
They seem to be a bit bone headed about the imperial measurement and seem to throw all sorts of arguments up as to why it is better than metric.

If that's the case, then why do they have a METRIC monetry system ?

Somewhere in the distant past, they were using the Pounds, Shilling and Pence, but with a bit of an argument with the Pommies, they decided to go it alone.

So, where and when, did they swipe the metric monetry system from?

If metric is Ssooo bad, then why do they persist with the almighty METRIC dollar, why not just go right back to the bloody ridiculous Pounds, Shillings and Pence system that they were using ?

mark

mardtrp
01-16-2010, 03:29 PM
Can anyone visualize 798949 KG's.

Yep, real simple, a tad under 799 ton.

mark

Uncle O
01-16-2010, 03:41 PM
Wow, has this thread gone way of topic or what ? :eek:

It seems that this argument about imperial and metric will be around for many years to come and the main 'stayers' for imperial measurment are/is the 'dumb':p Yanks.
They seem to be a bit bone headed about the imperial measurement and seem to throw all sorts of arguments up as to why it is better than metric.

If that's the case, then why do they have a METRIC monetry system ?

Somewhere in the distant past, they were using the Pounds, Shilling and Pence, but with a bit of an argument with the Pommies, they decided to go it alone.

So, where and when, did they swipe the metric monetry system from?

If metric is Ssooo bad, then why do they persist with the almighty METRIC dollar, why not just go right back to the bloody ridiculous Pounds, Shillings and Pence system that they were using ?

mark


Mark,
it would appear that you started the whole pissing match back in post # 5
by inferring the Imp. system to be inferior.
If you find it to be so difficult to use by all means don't strain your tiny cranium in attempting to do so. We wouldn't want you to stroke out....
As it has been noted and stated we have no difficulty using both systems,
and switching back and forth is done with relative ease.
Except for you and some others who insist on bashing us "dumb yanks" for NOT using YOUR preferred or perhaps only known way of measuring, I only see us "Dumb yanks" showing you the folly of your ASSertion that yours makes sense and ours doesn't.
Now , don't be such a wanker and go piss off eh ?

Peter N
01-16-2010, 04:38 PM
Mark,
it would appear that you started the whole pissing match back in post # 5
by inferring the Imp. system to be inferior.
If you find it to be so difficult to use by all means don't strain your tiny cranium in attempting to do so. We wouldn't want you to stroke out....
As it has been noted and stated we have no difficulty using both systems,
and switching back and forth is done with relative ease.
Except for you and some others who insist on bashing us "dumb yanks" for NOT using YOUR preferred or perhaps only known way of measuring, I only see us "Dumb yanks" showing you the folly of your ASSertion that yours makes sense and ours doesn't.
Now , don't be such a wanker and go piss off eh ?

Actually I think I'd probably have to agree with all that:D
As another one who uses both and finds them equally as good in most cases, I'd also have to say that in the majority of cases I think metric measurements are simpler to use.
However I still flick the DRO onto inches when I'm using the edge finder then switch back to mm after it's zero-ed, it just seems easier that way but perhaps it's a personal quirk.

Whilst I wouldn't try hard to persuade anyone to change from the system they understand well and are comfortable with, it's worth asking the dyed-in-the-wool sceptics on both sides to try and understand the 'other' system better before dismissing it out of hand as useless.

Peter

nheng
01-16-2010, 04:48 PM
Somewhere in the bowels of this forum is a thread on where the "10" in 10-32 comes from.

I considered going completely metric in the home shop since I use it heavily at work (fiber / optics) too. I found that the hardware just ain't there (in many ways) although the prices are.

Den

John Garner
01-16-2010, 04:49 PM
mardtrp --

Your calling the U.S. monetary system "metric" caught me off guard, so I looked up the word "metric". The relevant definitions can be summarized either as 1) a measurement system having meters, kilograms, and second as the basic units, or 2) a standard for measurement.

Since the U.S. monetary system isn't commonly measured in meters, kilograms, or seconds, I have to presume that the second definition is appropriate to the thought you expressed.

Now that I understand what you have said, I can reply.

Thank you. Although only one of a large number of people concerned about the world's present economic situation, I certainly hope that the U.S. monetary system continues to set the standard against which other monetary systems are measured and judged.

Incidentally, it's an interesting coincidence that the basic units of the meter-kilogram-second metric system are decimally divided, as is the basic unit of the U.S. monetary system, the U.S. dollar.

John

vpt
01-16-2010, 05:01 PM
I'm with John from the UK, metric is easier.

It is overtaking the US more and more. The sooner you learn it and except it the better off you will be.

7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1

Or

10mm, 11mm, 12mm, 13mm, 14mm, 15mm...

loose nut
01-17-2010, 11:55 AM
mardtrp --

Your calling the U.S. monetary system "metric" caught me off guard, so I looked up the word "metric". The relevant definitions can be summarized either as 1) a measurement system having meters, kilograms, and second as the basic units, or 2) a standard for measurement.

Since the U.S. monetary system isn't commonly measured in meters, kilograms, or seconds, I have to presume that the second definition is appropriate to the thought you expressed.

Now that I understand what you have said, I can reply.

Thank you. Although only one of a large number of people concerned about the world's present economic situation, I certainly hope that the U.S. monetary system continues to set the standard against which other monetary systems are measured and judged.

Incidentally, it's an interesting coincidence that the basic units of the meter-kilogram-second metric system are decimally divided, as is the basic unit of the U.S. monetary system, the U.S. dollar.

John


People confuse Metric with decimal.

Metric, Imperial measurement and U.S. money are all decimal but only Metric is Metric.

The Imp./Metric argument is like talking about different and or lack of religions, best not to go there, you will never agree on anything, because the other guy is always wrong.

Here is a question for the Brits or Aussies/kiwi's, if you go to a lumber yard to buy some studs do you ask for 50 x 100 mm's or do you still ask for 2 x 4's.

Timleech
01-17-2010, 12:08 PM
People confuse Metric with decimal.


Here is a question for the Brits or Aussies/kiwi's, if you go to a lumber yard to buy some studs do you ask for 50 x 100 mm's or do you still ask for 2 x 4's.

Neither, it would be the larger dimension first, so 100 x 50 or 4 x 2.
Either of those, probably.

Oh, and we don't have lumber yards in the UK :D
Timber yards, before and after metrication.
To the best of my knowledge, hardwood is still sold here in Imperial dimensions but softwood in metric, and plywood still comes in actual 8' x 4' sheets to a metric thickness but if you ask for an 8' x 4' of 6mm steel plate you get 2550 x 1250mm

Tim

J Tiers
01-17-2010, 12:12 PM
To the best of my knowledge, hardwood is still sold here in Imperial dimensions but softwood in metric, and plywood still comes in 8' x 4' sheets to a metric thickness.

Tim

And here, plywood comes in metre dimensioned pieces as well as 4 x 8

J Tiers
01-17-2010, 12:16 PM
I'm with John from the UK, metric is easier.

It is overtaking the US more and more. The sooner you learn it and except it the better off you will be.

7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1

Or

10mm, 11mm, 12mm, 13mm, 14mm, 15mm...

You don't state your location.... probably far from teh US....

Carpenters use fractions.... because they always have.

Anyone else who makes an accurate measurement uses decimal.....

All "furriners" compare only fractional with the decimal metric, and apparently assume that US machinists make measurements to 512ths of an inch :rolleyes:

The one and sole real benefit to using metric in daily life is simply because it is so widespread......

It would be nice if metric were standardized as well, but just because it is widespread means it is a functional decision to use it, warts and all.

tyrone shewlaces
01-17-2010, 12:23 PM
... and plywood still comes in actual 8' x 4' sheets to a metric thickness

Ha. Kind of like the failed Mars orbiter project?

That's the case over here too. I think every year or few they make it 1mm thinner.
Now there's a non-standard for you. Lumber.
What is the point as you approach 1" where you can no longer label something to be 2". It gets compressed thinner ever few years.

vpt
01-17-2010, 12:28 PM
You don't state your location.... probably far from teh US....



I thought I had my location listed in my profile. I live in stevens point, WI

loose nut
01-17-2010, 12:31 PM
Neither, it would be the larger dimension first, so 100 x 50 or 4 x 2.
Either of those, probably.

Oh, and we don't have lumber yards in the UK :D
Timber yards, before and after metrication.
To the best of my knowledge, hardwood is still sold here in Imperial dimensions but softwood in metric, and plywood still comes in actual 8' x 4' sheets to a metric thickness but if you ask for an 8' x 4' of 6mm steel plate you get 2550 x 1250mm

Tim

I'm guess that you still quote 4 x 2's or 8' x 4' sheets because it is easier then asking for a 2550 x1250 mm sheets. For some things Imperial is better then Metric.

Timleech
01-17-2010, 12:44 PM
I'm guess that you still quote 4 x 2's or 8' x 4' sheets because it is easier then asking for a 2550 x1250 mm sheets. For some things Imperial is better then Metric.

The steel stockholders, at least my local one, do talk in metric dimensions but know what you want if you give the imperial sheet size.
I use steel in 2m x 1m and 2550 x 1250 (or is it 1225? not so sure now ;) ) and am quite likely to place an order on the phone for " 2 No. 2 x 1 x 5mm, 3 No. 8 x 4 x 6mm" and they'll know exactly what I mean. I think if I asked for a 6 x 3 of 5mm they would query my meaning to be certain.

Tim

J Tiers
01-17-2010, 04:07 PM
I'm guess that you still quote 4 x 2's or 8' x 4' sheets because it is easier then asking for a 2550 x1250 mm sheets. For some things Imperial is better then Metric.

Noted.........


Where is the unit for people-size measurements? Metres are too big, you need too many decimal places. MM get ridiculous as you get into thousands of them.

"Oh, it's about 1.21 metres"............ that's just silly. but "it's about 4 feet" is perfect.

That is the good thing about inches... they are "right sized" for people-size stuff. Even feet are a good unit for people-sized stuff. Metres are not, way too big.

Your Old Dog
01-17-2010, 06:24 PM
............................
Of course it doesn't get a simpler than Metric..but I won't go there

Rich

Anybody within back-of-the-head-slapping range of Rich? :D

bob ward
01-17-2010, 08:19 PM
Here is a question for the Brits or Aussies/kiwi's, if you go to a lumber yard to buy some studs do you ask for 50 x 100 mm's or do you still ask for 2 x 4's.

In Oz and NZ lumber is not a word in common use, its all timber which is bought at the timber yard. Mention lumber and you are likely to have someone start singing the Monty Python lumberjack song. :D

Timber sizing convention here, same as the UK, is always large size first eg 6 x 2 or 150 x 50. How you refer to the timber size depends on whether you are talking about pine studs, or rough sawn hardwood.

Pine studs, since not long after metrification in the mid 70s, have been produced in metric sizes only, 70 x 35, 70 x 45, 90 x 35 and 90 x 45. Soft imperial conversions don't work with those sizes so they are only referred to in metric sizes.

Rough sawn eucalyptus hardwood on the other hand, is produced in metric equivalents of the old inch sizes, so you can refer to an either 8 x 3 or a 200 x 75 and you will get a 200 x 75.

Timber lengths in either pine or hardwood are in 300mm increments, ask for 10 footers and you get 3 metres.

The guys at the timber yard speak both metric and imperial, so you can ask for 8 foot of 70 x 45 pine or 2.7m of 4 x 2 hardwood and no one bats an eyelid.

loose nut
01-18-2010, 07:42 PM
Here abouts timber is a tree in the forest about to become lumber, lumber is what you get after cutting a piece of timber into long rectangles.

We quote lumber with the small # first IE: 2 x 4, 4 x 8 etc, same thing only different.

John Stevenson
01-18-2010, 07:48 PM
The true reason we use the larger size first like 4 x 2 is when you whack someone round the bonce you get to use the widest side so have less chance of missing.

.

form_change
01-19-2010, 05:15 AM
Here in Oz a tree is called a tree. When it's cut it becomes timber and lumber is how you describe someone walking with a heavy or clumsy gait.

(What ever happened to the furious arguement about metric vs. imperial? Perhaps we should all work in dioptres...)

gvasale
01-19-2010, 06:39 AM
two men of unknown ethnithcity go to a lumber yard to buy some wood. One of them waits in the car, the other goes inside to place an order. The purchaser goes inside and is asked by the clerk what he wants. The purchaser says "I need some 4"x2"s." The clerk says " you must mean 2"x4"s."

The purchaser, looking puzzled, says "let me go and check with my friend who is in the car" Back in the store, he says to the clerk "you're right, I need 2'x4's" The clerk says "How long do you want them?" The purchase says, "let me check" and goes outside.

Returning back inside, he says to the clerk " I need them for a long time. I'm going to build a house."

andywander
09-06-2013, 11:17 PM
...ask for a 1/2" bolt and 95% of the time you will be given a 1/2-13....

andywander
09-06-2013, 11:19 PM
Just to add a bit of interest to our lives...the tapped holes in those aluminum 19" server/relay/telecom racks full of high tech equipment are usually#12-24.

well, some of them are.....many are also 10-32.

Juergenwt
09-06-2013, 11:25 PM
You don't know what you are talking about. Sorry!

Juergenwt
09-06-2013, 11:29 PM
John,
Here in the Simple US, it's always the specials...

The biggest problem I run into here, is a lot of the US Metric Bolt heads are 1 mm bigger than EU metric bolts...

Fun In tight spaces.. EU is used to that, I'm sure :)

61.1 Million Brits ought to be able to tell Us 300 million plus, to get it right :)

More BS!

Juergenwt
09-06-2013, 11:36 PM
when you go to the hardware store, anybody worth a damn will know to ask you "coarse or fine thread pitch?" when you ask for that 1/2" bolt...

You just ask for M12 - Period! Only in metric challenged US will they ask for the pitch. If for some ungodly reason you need a "Fine Pitch" -ask for it!

Juergenwt
09-06-2013, 11:55 PM
No. One standard with fine and course pitch. Metric has fine and course as well. Metric and imperial both also offer "special" threads but that's just stupid in most cases and we won't go there. No advantage of one over the other. The problem is that switching to metric takes tons of cash for tooling, so demanding that the manufacturing behemoth the US once was to change to metric because some French wussy, bottle-glasses Beaker scientist could then just move the decimal instead of having to remember a conversion factor just wasn't going to happen.



Yea and over here he'll bring you a 1/2-13. If you want fine pitch, then you'll have to send him back a second time.

I don't see why anyone thinks there's such an advantage to metric. The metric bolt notation even looks clumsy to me. Ever screw up and read 1.25 to be 1.75 for a pitch and vise-versa? That's the problem with metric. You want to be lazy and just move a decimal place? Fine. Now you have decimals in everything because you aren't allowed to just divide something up anymore. Especially if it's thirds or something. Oh God - Blasphemy! 1/3rd of a centimeter? Unheard of! Why? (I think the American engineers picked 13 for the pitch of a 1/2" bolt just as a jab to the metric fans. "1/13 of an inch? Is that even allowed?" hehe.)
I think people who love metric are the same type who hate fractions or something. US units are good for learning fractions. Units are supposed to be something divided up to begin with right? Whomever limited the divisions to only 10 was just short-sighted. Why not be able to divide something into whatever unit is the most useful instead of arbitrarily picking 10? THAT'S right - I called metric "arbitrary" and I meant it.

If a guy is not good with numbers, he's not going to be much good in either system. He'll be able to blame the "other" system though, so he's got that going for him.

The world will NEVER settle on a single standard I don't think. Unless metric could include the two most universal units in the universe, it will never take off. I'm speaking, of course, about the units of HH and FF. These are used more than any other unit in history and their intuitive relationship to all things is apparently undeniable. It's the newscasters' standard measure and the abbreviations of course stand for Human Hair and Football Field.

This silly "metric system" thing doesn't stand a chance.

"takes tons of cash" - another guy who does not know what he is talking about. When GM changed to metric they anticipated an enormous amount of money to be spent on the conversion. They ask the government for tax relieve for all the money spent to convert to metric. 1.they
found out it cost less than 1% of what they had estimated and by the third year they dropped all claims for tax relieve because the savings from going metric far exceeded the cost.
Look here: http://lamar.colostate.edu/~hillger/pays-off.html#gm

Juergenwt
09-07-2013, 01:12 AM
Those " Imperial People" will fight on till death along with their friends in Liberia and Myanmar. They don't understand that the Metric train left the station long, long ago. They will keep on selling inch/pound/gallon/ Fahrenheit products as long as they find a buyer. After all - the horse and buggy worked just fine. Why change it. And the US used to be the leader! Right? All of this because we had a President (Regan) who was still in the age of the "Charge of the light brigade" and a Government unable to look past the next election. In the mean time the country suffers. Cans of food that give the weight in ounces and the ingredients in grams. Children unable to do math because the have to jump from metric to imperial. Industry fighting a running battle with product for sale in metric and engineers mired in the imperial system. Travelers being called stupid because they don't know how far 1 Km is. The list goes on and on. The next time you buy 325 mg aspirin pls tell me how much in imperial? If you have a 12 oz can of beer - how many in a barrel? But on and on they go fighting for the "Foot". And talking about a "foot" - why is it even called Football? That is just plain dumb! May be we should call it "Carry Ball" or American Rugby.

dfw5914
09-07-2013, 01:56 AM
...and why yellow is clearly superior to orange.

dfw5914
09-07-2013, 02:03 AM
Ssshhh Tim,
Don't let on that old Joseph who set the first standards up before American was even found and used 55 degrees with rounded roots and flanks is still the strongest thread form to date.

.

...and why metric threads are 55 degrees with rounded roots.

dfw5914
09-07-2013, 02:05 AM
...Metric threads are 55 degrees with rounded roots, yes?

dfw5914
09-07-2013, 02:09 AM
If not, then why not?

Paul Alciatore
09-07-2013, 02:22 AM
Just to add a bit of interest to our lives...the tapped holes in those aluminum 19" server/relay/telecom racks full of high tech equipment are usually#12-24.

Only the computer nerds and the telephone people are stupid enough to use racks with 12-24 holes. The radio and TV industry uses 10-32. I have bought dozens of the racks and thousands of the screws. Always 10-32.

DATo
09-07-2013, 04:51 AM
The switch from Inch to Number measuring for "small" threads produced some
wierdcases. These are generally threads less than 1/4"
In Number Screw sizes, You start with .060 as a base and it is a 0-80 thread, or 0-72 etc.
( Please note that .0625 is 1/16 , so " )" is close to that fraction benchmark)
Each sequential thread size grows by .013" and gains one digit.
A 1-72 for example is .073" and a 2-56 is .086 in the "Major Diameter" measurement.
A 10-32 is .060 PLUS .130 ( 10 x .013) or .190
Your old 3/16 thread is .1875"
The only "exact" one is 1/8-40 (ie.) as it meets a 5-40 (.060+.065) at .125 dead on.

Real confusion is with the #14 threads (.060 + .182) as its .242
So if you have a 1/4 -20 bolt, it will not fit a 14-20 hole !

Old machines and hardware still use the old standard of 100 ago

Its a lot easier, to refer to numbers than fractions.
Can you imagine doing a 5/64-72 or a similar ?
It was an attemp to make the range smaller than 1/64's
Of course it doesn't get a simpler than Metric..but I won't go there

Rich

Excellent post Rich !

Don't mean to nitpick but I just wanted to mention that the number series screws actually start with "quad-aught" 160's (0000-160) which have a major diameter of only .021" dia. The smallest I have ever seen are triple aught 120's with an O.D. of .034" and we actually have them as well as the taps in our shop. I can no longer see the threads without a magnifying glass. To be honest I can't remember the last time we used them though but we have used them - it's been probably literally decades ago as near as I can recall.

WhatTheFlux!
09-07-2013, 08:35 AM
"Uh this machine is set to metric, how do I set it back."

"You can't it's Canadian."

"Ok, so what's 310 in F then?"

"Hot enough to melt nylon."

"...Yeah but I need to know what it is in F."

"No you don't. Just go with it."

"And what the hell is BAR? And everything is in MM. I can't run this."

"We've run it for three years without issue, maybe the problem is you?"

"No the problem is the machine uses non-standard measurments that I don't understand and I'm not about to learn. THIS IS AMERICA the rest of the world should be using our measurment system... not some system invented in France. What the **** is wrong with that picture? That's right, FRANCE. I REFUSE to use anything produced by the French or invented by the French."

"Ok... you're fired. Plain and simple. No one else had a problem with this, and on top of that while I have no great love of France or French culture we do have French and French-Canadian customers. Can't have you badmouthing the folks who pay us."


----
This happened about six weeks ago. His attitude changed real quick, started backpeddling real fast when I threatened him. Now he's "down" with metric.

I never had any issue switching from one to the other, and I can think in metric just fine. Never had a issue. Only time problems cropped up for me was during conversion. That's when I decided to just think in metric for those applications rather than screw around with numbers.

Shade
09-07-2013, 09:04 AM
The best reason NOT to use the Metric system... it's French...

WhatTheFlux!
09-07-2013, 09:22 AM
Hating on the French is soooooo 10 years ago. Get with the times man. ;)