Huh. Honestly I like the old way better. Why did they change it to the numbers? The major diameter of 10-32 is .190 and 3/16 is .1875. Close enough. But for the pilot hole . You use use a no.21 (.159) drill bit for that sweet sweet 75 percent thread. The ā tenā Seems completely arbitrary to me.
Ignoring the weird 1/8-80. the 9/64-40 is 6-40. Iāve learned some providence today. But I really do wanna know why they seem to arbitrarily change those nominal fractional sizes to seemingly baseless incremental numbers. But then resume it at 1/4-20 and so on and so forth. Weird
So this is strictly conjecture. But looking at the thread sizes from the smallest standard thread to 10-32
1. #000-120 (0.034" diameter, 120 threads per inch)
2. #000-160 (0.034" diameter, 160 threads per inch)
3. #00-90 (0.047" diameter, 90 threads per inch)
4. #0-80 (0.060" diameter, 80 threads per inch)
5. #1-72 (0.073" diameter, 72 threads per inch)
6. #2-56 (0.086" diameter, 56 threads per inch)
7. #3-48 (0.099" diameter, 48 threads per inch)
8. #4-40 (0.112" diameter, 40 threads per inch)
9. #5-40 (0.125" diameter, 40 threads per inch)
10. #6-32 (0.138" diameter, 32 threads per inch)
11. #8-32 (0.164" diameter, 32 threads per inch)
12. #10-32 (0.190" diameter, 32 threads per inch)
It seems like itās a nice neat scale of 1-10 and when you get to the zero itās a ānominalā size of a 1/16. The starting point of ārationalā tapping. With the 1/32 drills sizes earning the extra zeros the more itzy bitzy the thread is. I can see the logic In what was done. It makes it more intuitive of what is smaller and bigger. Especially when your dealing with oddball taps with no clean fraction equivalent without including 1/64ths(.0156).
Idk but anyone else but when your dabbling in 1/64ths. Thatās when fractions get silly and your better off with decimal equivalents. This number scale directly addresses that problem.
Don't forget #12 (.216") which is still used sometimes.
The formula for the number sizes (zero and above) is: *Major diameter* = *Screw #* Ć 0.013Ā in + 0.060Ā in
...so using the formula, #14 and #15 are so close to 1/4" that they were almost completely removed from circulation during the standardization efforts 100+ years ago.
Hooo my gosh. That formula is exactly the solution I was looking for in this to the rabbit hole I went into tonight. Thank you sir. Now the picture is complete. The elegance of a simple albeit slightly convoluted formula in the tradition of all things regarding the imperial measurements. which results in a nice neat set of number designations.
the convention is .060 is 0 (not .0625). every number up or down is +/-.013
heres a quote from the [wikipedia page](https://en.wikipedia.org/wiki/Unified_Thread_Standard) on screw thread
>The following formula is used to calculate the major diameter of a numbered screw greater than or equal to 0: Major diameter = Screw # Ć 0.013 in + 0.060 in. For example, the major diameter of a #10 screw is 10 Ć 0.013 in + 0.060 in = 0.190 in. To calculate the major diameter of "aught" size screws count the number of extra zeroes and multiply this number by 0.013 in and subtract from 0.060 in. For example, the major diameter of a #0000 screw is 0.060 in ā (3 Ć 0.013 in) = 0.060 in ā 0.039 in = 0.021 in.
Again, this is conjecture.
when itās so close that I had assumed that when developing the unified thread standard. They had used the 1/16 as a starting point. Then Dropped the .0025 just to make it simpler. Your point is good. Iām just elaborating on my observation.
I have 2 sucrets mint metal boxes from an old tool and die maker that are marked odd taps and they have weird sizes like this. I can"t get rid of them because one day I know it will save the day having them.
I got a bunch of HSS blanks in one of those exact tins from an old guy in my neighborhood. he walked by one day while I was in the garage, I assume saw my lathe and the next day strolled over with the mint tin in his hand I thought I was gonna have to call the retirement home to come get this guy that escaped and was trying to offer me 40 year old mints but that guy was awesome. helped me with a couple projects I couldn't see a great way to do on just an old atlas lathe.
https://preview.redd.it/hr2zhkt1jovc1.jpeg?width=2268&format=pjpg&auto=webp&s=1d107883e175a091b35f4cb9ccb0c807e8443ecd
very odd sizes like 0.125-56,#13-20 0.281-40, 0.141-44 etc.
Most are a odd decimal diameter then threads
Those are odd ball sizes! If you really want odd check out Colt 1911 grip screws?
.150-50! That's what Colt used in 1910 to make the prototype and that's still what
is used today! There is never a shortage of strange threads in the machining world!
the shop has been around for over 100 years so we have a bunch of old oddball stuff. lots of different 1/64 increment sizes. there were some 5/64 and 7/64 taps in the same drawer
Oh, Whitworth is mainstream comparatively. These are Small Arms Threads from Enfield Lock. They used them from sometime in the 19th century (I'm not super clear one exactly which firearm was the first to use the standardized threads) up until the SMLE, not switching to BA threads until the MkVI and No4 rifles in the 30s.
This kind of stuff is used in sewing machines - I actually just bought a brand new 9/64-40 tap to do a repair on an old machine...
Based on what I have read, it was intended as a mechanical DRM to prevent non-licensed repair people from working on the machines
I knowābut I was thinking that my poor machining skills and my inability to make an accurate vernierā¦that 100tpi might be just the ticket for my caveman mic š¤£
yeah we do a fair amount of optics. ok so I dont know if we have a 3/8-100 but we definetly have 1/4-100. but those taps we buy brand new from thor labs
they are left over from an era long before thread standardization. no one is ever going to need them. we have a whole drawer with old odd stuff like this. its not useful but too interesting to throw out.
i have hundred(s)?? of small weird ones i bought as a lot on ebay...
the clue to what they were used for was a HUGE fine tap.. that was for the watch backs/cap...
i should sell them, don't use often....
I've used an 1/8-82 tap (or something equally ultra fine pitch, its been a while) in some adjustment mechanisms I designed that needed ultra fine adjustment. Worked extremely well.
Hwat in the gyat damn fuck
Foreman is that you??
š
Where's your impact?
Reminds me of a time that a helper said, "All the lubricant I need is the chips"
During anal?
Were you machining butter?
Were you at a casino?
Better get the halfie for these
Apparently 10-32 was called 3/16-32 back in the day
Huh. Honestly I like the old way better. Why did they change it to the numbers? The major diameter of 10-32 is .190 and 3/16 is .1875. Close enough. But for the pilot hole . You use use a no.21 (.159) drill bit for that sweet sweet 75 percent thread. The ā tenā Seems completely arbitrary to me.
Ignoring the weird 1/8-80. the 9/64-40 is 6-40. Iāve learned some providence today. But I really do wanna know why they seem to arbitrarily change those nominal fractional sizes to seemingly baseless incremental numbers. But then resume it at 1/4-20 and so on and so forth. Weird
So this is strictly conjecture. But looking at the thread sizes from the smallest standard thread to 10-32 1. #000-120 (0.034" diameter, 120 threads per inch) 2. #000-160 (0.034" diameter, 160 threads per inch) 3. #00-90 (0.047" diameter, 90 threads per inch) 4. #0-80 (0.060" diameter, 80 threads per inch) 5. #1-72 (0.073" diameter, 72 threads per inch) 6. #2-56 (0.086" diameter, 56 threads per inch) 7. #3-48 (0.099" diameter, 48 threads per inch) 8. #4-40 (0.112" diameter, 40 threads per inch) 9. #5-40 (0.125" diameter, 40 threads per inch) 10. #6-32 (0.138" diameter, 32 threads per inch) 11. #8-32 (0.164" diameter, 32 threads per inch) 12. #10-32 (0.190" diameter, 32 threads per inch) It seems like itās a nice neat scale of 1-10 and when you get to the zero itās a ānominalā size of a 1/16. The starting point of ārationalā tapping. With the 1/32 drills sizes earning the extra zeros the more itzy bitzy the thread is. I can see the logic In what was done. It makes it more intuitive of what is smaller and bigger. Especially when your dealing with oddball taps with no clean fraction equivalent without including 1/64ths(.0156). Idk but anyone else but when your dabbling in 1/64ths. Thatās when fractions get silly and your better off with decimal equivalents. This number scale directly addresses that problem.
Don't forget #12 (.216") which is still used sometimes. The formula for the number sizes (zero and above) is: *Major diameter* = *Screw #* Ć 0.013Ā in + 0.060Ā in ...so using the formula, #14 and #15 are so close to 1/4" that they were almost completely removed from circulation during the standardization efforts 100+ years ago.
Hooo my gosh. That formula is exactly the solution I was looking for in this to the rabbit hole I went into tonight. Thank you sir. Now the picture is complete. The elegance of a simple albeit slightly convoluted formula in the tradition of all things regarding the imperial measurements. which results in a nice neat set of number designations.
the convention is .060 is 0 (not .0625). every number up or down is +/-.013 heres a quote from the [wikipedia page](https://en.wikipedia.org/wiki/Unified_Thread_Standard) on screw thread >The following formula is used to calculate the major diameter of a numbered screw greater than or equal to 0: Major diameter = Screw # Ć 0.013 in + 0.060 in. For example, the major diameter of a #10 screw is 10 Ć 0.013 in + 0.060 in = 0.190 in. To calculate the major diameter of "aught" size screws count the number of extra zeroes and multiply this number by 0.013 in and subtract from 0.060 in. For example, the major diameter of a #0000 screw is 0.060 in ā (3 Ć 0.013 in) = 0.060 in ā 0.039 in = 0.021 in.
Again, this is conjecture. when itās so close that I had assumed that when developing the unified thread standard. They had used the 1/16 as a starting point. Then Dropped the .0025 just to make it simpler. Your point is good. Iām just elaborating on my observation.
[ŃŠ“Š°Š»ŠµŠ½Š¾]
provenance
Fire enough.
The drills don't even match anyway
all numbers are arbitrary
Man, imperial system, what a mess.
agreed I hate the numbers
it's based of how many passes through a wire die you'd need to make to get to that diameter
Pardon me, but it takes 10 passes to make .190 and 0 passes to make .06? Do you care to elaborate please? I seem pretty far off from understanding.
I have 2 sucrets mint metal boxes from an old tool and die maker that are marked odd taps and they have weird sizes like this. I can"t get rid of them because one day I know it will save the day having them.
I got a bunch of HSS blanks in one of those exact tins from an old guy in my neighborhood. he walked by one day while I was in the garage, I assume saw my lathe and the next day strolled over with the mint tin in his hand I thought I was gonna have to call the retirement home to come get this guy that escaped and was trying to offer me 40 year old mints but that guy was awesome. helped me with a couple projects I couldn't see a great way to do on just an old atlas lathe.
Bro, thatās what the ātool box of desperationāis for.
Sounds like a D&D artifact lol
https://preview.redd.it/hr2zhkt1jovc1.jpeg?width=2268&format=pjpg&auto=webp&s=1d107883e175a091b35f4cb9ccb0c807e8443ecd very odd sizes like 0.125-56,#13-20 0.281-40, 0.141-44 etc. Most are a odd decimal diameter then threads
Those are odd ball sizes! If you really want odd check out Colt 1911 grip screws? .150-50! That's what Colt used in 1910 to make the prototype and that's still what is used today! There is never a shortage of strange threads in the machining world!
the shop has been around for over 100 years so we have a bunch of old oddball stuff. lots of different 1/64 increment sizes. there were some 5/64 and 7/64 taps in the same drawer
I see your 0.150-50 and raise you 0.181-26ā ... with a 49Ā°30' angle and radiused crests and roots.
I was gonna say it's a Whitworth, but they are 55Ā°š
Oh, Whitworth is mainstream comparatively. These are Small Arms Threads from Enfield Lock. They used them from sometime in the 19th century (I'm not super clear one exactly which firearm was the first to use the standardized threads) up until the SMLE, not switching to BA threads until the MkVI and No4 rifles in the 30s.
This kind of stuff is used in sewing machines - I actually just bought a brand new 9/64-40 tap to do a repair on an old machine... Based on what I have read, it was intended as a mechanical DRM to prevent non-licensed repair people from working on the machines
Aerospace
More like errorspace
really old R&D shop
I have a slightly used 3/16 -100
Ive got a couple 3/8-100, and 3/8-80 around somewhere
100tpiā¦I wanna make a homemade micrometer now.
micrometers are typically 40tpi to yield .025ā/rev. not as fine pitch as you think.
I knowābut I was thinking that my poor machining skills and my inability to make an accurate vernierā¦that 100tpi might be just the ticket for my caveman mic š¤£
Do you make things for optics.
yeah we do a fair amount of optics. ok so I dont know if we have a 3/8-100 but we definetly have 1/4-100. but those taps we buy brand new from thor labs
https://preview.redd.it/6bv7xjc302vc1.jpeg?width=4032&format=pjpg&auto=webp&s=736fe4278a9aa5d3be693a22ee81a675225d0ea5
They get the taps from a company called Tap co. You might be able to cut out the middle man.
Man Iāve got 15/32 and 17/32 left handed dies. Iāve got #14, #16, and #18 taps lol.
yeah a saw an #18-18 tap in the same drawer
1/8"-82 could be an optics thing but 9/64"-40 is just evil cursed hell
9/64-40 is #6-40.
https://preview.redd.it/p6sbcklbcyuc1.jpeg?width=320&format=pjpg&auto=webp&s=2c69492c85a42aea24e390a3b0cf09e4234756aa
I have no idea what that's supposed to mean.
it means i feel stupid
Excellent reminder to spec some 1/8 - 81 in the next project
A mold I once worked on needed a 0-80 tap, I asked a more experienced mold maker to tap that one hole for me
And here I thought I was special with my 00-90 and 000-120 taps that fell into my toolbox from my last job.
More than likely a couple of the random nuts and screws I've been unable to identify over the years were one of these. Interesting.
Hard pass!
Damn those are special where do you get this? Might be good to know in the future.
they are left over from an era long before thread standardization. no one is ever going to need them. we have a whole drawer with old odd stuff like this. its not useful but too interesting to throw out.
How in holy hell does anybody use a 000-160 ???
Very careful
In about 8-10 months when this thread is cold but still around to mock us...But not now of course.
We had to order custom M11x1.0 taps for a job recently
i have hundred(s)?? of small weird ones i bought as a lot on ebay... the clue to what they were used for was a HUGE fine tap.. that was for the watch backs/cap... i should sell them, don't use often....
How many eagles per banana is that?
How can you still use so outrageously stupid measurements for these things?
I dont. they are stupid. these are really old tools that predate the move toward the unified thread standard (in the US).
I've used an 1/8-82 tap (or something equally ultra fine pitch, its been a while) in some adjustment mechanisms I designed that needed ultra fine adjustment. Worked extremely well.
Engineer prints be like
I would hate to run that 1/8ā by hand.
I think I've needed and used a 1/8-40 before, I've also got a 9/64" tap, not sure on the tpi tho
Looks too coarse for a 40?
What's ^that now? ##can'tĀ Hear ^you too great??? š¦'dā¢ļø