thread pitch question

[linde]

What is the thread pitch between the extractor rod and extractor ratchet shaft? When I measure, I get #10 with 64 tpi . . . left hand! Not exactly a pitch included in your average starter tap & die set!

If it makes a difference, I'm working on a 5-screw improved I-frame Terrier s/n 71720 from circa June-1953.

Whatever size it is, where can I get both a tap and die?

Russ

 

[Mike McLellan]

In the Neal / Jinks book is a reference to that pitch being changed to 7 x 47. I think that it may be a typo, but I pretty much quit looking for the proper tap when I read that! I would love to have a tap & die to tidy up the threads on an extractor rod.

 

[linde]

I just found this old thread that kinda-sorta clarifies things.

http://smith-wessonforum.com/s-w-smithing/195799-10-46-thread.html

I'm satisfied we're dealing with a #10 (.183"-.186" diameter) but I'm a long way from getting 46, 47 or 48 tpi. Will try to find a left-hand 10-48 tap & die . . . wish me luck.

Russ

 

[WillMcLap]

I just found this old thread that kinda-sorta clarifies things.

10-46 thread

I'm satisfied we're dealing with a #10 (.183"-.186" diameter) but I'm a long way from getting 46, 47 or 48 tpi. Will try to find a left-hand 10-48 tap & die . . . wish me luck.

Russ

linde,
I know this is old thread but I am facing same problem now wanting to clean up threads on extractor rod on an old model 36. Were you able to find a 10-48 die that would allow you to chase the threads?
Was 48 Correct TPI?

 

[WR Moore]

Brownells has some Swiss files that are extremely good. Get a triangular file and VERY carefully chase the male threads.

When you get into the special fine threads, the dies & taps can cost as much or more than replacement parts.

 

[Hondo44]

Those are "fast twist' threads. Only cut with a screw machine. Don't make taps and dies for those to my knowledge.