# Cap threads



## pipecrafter (Dec 8, 2008)

Most of you have probably seen this pen in the show-'n-tell section, but I figured I'd start a new thread here with stuff I learned while making it.

The pen (click for bigger):


 

 



That's a berea front section, and while an M10x1 tap made the right sized threads, I used a letter Q drill bit to make the hole, which resulted in the threads being far too tight.  I went back in and reamed it out with an 11/32" bit, and the fit is pretty damn good.  The next time I do this, I'll just skip right to using that drill size to cut the hole.

The cap threads are single start 1/2"-32.  When I was finished yesterday, it took 6 full rotations to seat or remove the cap.  Today I modified the cap by drilling out the first three threads, now it seats with only 3 full turns.  Ah!!  Geometry!!  3 full turns may not be on par with multi-start threads that require one full turn, but IMO, it's pretty good.  Unfortunately, a multi-start tap and die are not in the cards for me right now - I simply cannot afford them.  

Hopefully these pieces o finfo will help folks out.


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## gwilki (Dec 8, 2008)

Nicely done, Kurt. It looks very fine.


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## Paul in OKC (Dec 9, 2008)

Nice work.


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