Hello everybody, I am planning on installing my EGT sensor this weekend and my question is what size drill bit should I use for a 1/8" NPT fitting?. Thanks in advance and Happy Hollidays!!

 

I bought the tap and it said to use a 7/16 drill bit, your tap should tell you what size drill bit to use. Good Luck!

 

Thanks for the quick reply. Merry Christmas everyone!

 

Normally the drill size is 75% of the tap size......heres a link to tap drill sizes

http://www.newmantools.com/tapdrill.htm

 

The tap/drill chart is great, but since it is using letter drills, I thought I'd give you the easy #. slighfox is giving you the drill size for 1/4" not 1/8".
Use 5/16". It will give you the correct thread % for 1/8" NPT, without going around looking for the letter drill.