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270685 Erik Levin 2020‑05‑01 Re: Threading die for 0.108-50
Thank you for the follow up.

Another day, another piece of useful trivia I learn. 7/64-50 is reasonable, and
if once standard, likely. I measured the pitch diameter at 0.0954, which would
be consistent with this. It amazes me how often I still run across new, outdated
"standard" threads, in particular that I can't find in references.

I conjecture that, no matter what the size, between one millimeter and one inch,
and thread pitch, within a factor of two of the current closest imperial or
metric standard, there will be a historical standard size that is, for all
practical purposes, indistinguishable.


Why I haven't gone to an adjustable die? I have nothing quite close enough to
make the size in the right pitch. The thread engagement is deep enough that
going off pitch (48TPI) won't do the job, and might damage the tools.


For reasons having to do with practicality, I am going to borrow time on an
unmentionable device to make these. As much fun as the hunt for the proper die
is, current circumstances make the unmentionable method most practical (the
machine time is free)


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On Friday, May 1, 2020, 11:21:59 AM EDT, John Ruth  wrote: 


Erik, 



Here’s a response from one of my correspondents:




“ I think it is 7/64” -50, that was a size used back in the day. I looked and I
have a .109”-50, it is #12 gauge Stubs IRON WIRE GAUGE, a bizarre set of sizes
that were used for bicycle spokes a[bout] 120 years ago. “



Before that, he’d suggested:

“...since these are for lock screws couldn’t he just use an adjustable jam die?
Or even a little giant type? I have often fudged a little with those.”



John Ruth

Reminded of his “non-buyer’s remorse” for passing up a very Antique jam die tool
at the Avenel Flea back in its heyday. I put it down because of the price. As I
changed my mind, the guy right behind me bought it!!!

Recent Bios FAQ