#10 screw and 3/16 screw

[loose nut]

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.

[tyrone shewlaces]

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.

[darryl]

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- %#$&^*!

[oldtiffie]

Tuns 'uv it

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

[John Stevenson]

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.

.

[whitis]

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.

[oldtiffie]

Jump

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:

[spope14]

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.

[J Tiers]

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.

[oldtiffie]

Unscrewed up

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.

[kc5ezc]

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.

[tyrone shewlaces]

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.

[Blueskys]

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.

[JoeCB]

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

[Rich Carlstedt]

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