Weird thread?

[Martin-Sy]

Thanks, That's a really useful document. I've probably got all that in other sources but not collated in size order.
Full marks to Mr. Pugh.

 

[Stueeee]

A very useful document. As well as the ones in the document Pete posted, there are a fair few other odd threads (some very odd) on these web pages: https://www.gewinde-normen.de/en/index.html

 

[RedOrZed]

Well you do have the option of simply re-making those posts to the measured diameters and pitches. Or if you want to simply clean out the internal threads you might single-point some silver steel and harden it to make a triangle tap which would clean up those threads nicely.

Back in the day many people make their own cutting tools and it might simply be that someone made a tap, then used the tap to make a split die then produced all of those posts with the tools they had made for the job.

Meanwhile, attached is a handy look-up reference for a lot of historical (and current) threads.

That's a super handy reference, thank you very much!

I'm starting to believe you're right, they just did their own thing for this. There's a load of ex-Wolverton works thread chasers in the garage, will try some of them.

 

[RedOrZed]

Postie delivered 1/4 32 UNEF tap today (not the China one, a good one)

Doesn't fit, too big.

Found the chasers and found some 32s. They seem to fit? 8mm brass is on order, turn it down and see what these do? Never used chasers and only have my little Rollo Elf lathe available.

Some pics of the chasers. Found them at the local scrap metal yard years ago, someone had dumped them! Shocking.

those big ones I'm going to try using as beading tools on the word lathe.