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Reference for Taping NPT threads

Posted: Sun Jan 06, 2008 4:57 pm
by socoj2
Have you guys found a reference for what size drill bit to use, when tapping threads for different NPT sizes..

1/8
1/4
3/8
1/2
3/4

Posted: Sun Jan 06, 2008 5:00 pm
by SpudMonster
Your Google-Fu is weak grasshopper.

http://www.korit.com/tapndrill.htm

Posted: Sun Jan 06, 2008 5:12 pm
by grumpy
SpudMonster wrote:Your Google-Fu is weak grasshopper.

http://www.korit.com/tapndrill.htm
sorry young padiwan but your google-force is weak also
that chart does not cover npt threads, try this one.
http://www.dentsport.com/gallery/v/dsg/tech/thread/

Posted: Sun Jan 06, 2008 5:19 pm
by MrCrowley
grumpy wrote:
SpudMonster wrote:Your Google-Fu is weak grasshopper.

http://www.korit.com/tapndrill.htm
sorry young padiwan but your google-force is weak also
that chart does not cover npt threads, try this one.
http://www.dentsport.com/gallery/v/dsg/tech/thread/
It does, check the bottom of the page :wink:

Posted: Sun Jan 06, 2008 5:40 pm
by grumpy
so it does, i didn't see see that. must remember to clone a new braincell :)

Posted: Sun Jan 06, 2008 6:08 pm
by jrrdw
Tapered drill bits/reamers work better. Once you get near the back of the pipe tap, they get real hard to turn in, if your tapping a straight hole.