Need to tap my oil pan to except a 12AN bulkhead fitting for my oil return. What drill bit is recommended?

 

not sure but if noone help you just take a bit and put fitting on top till you find that matches...

 

Ive always just drilled a hole in the pan and got a nut for the other side of the fitting and used silcone to seal it...Worked great just upgraded to a moroso pan

 

1an = 1/16 inch,
2an = 2/16 inch,
3an = 3/16inch...etc,etc These are all OD, the ID can vary depending on the hose

12an = 12/16inch = 3/4inch
however you need to measure your fitting sometimes the welded end is different sizes, or use a bulkhead fitting.....
you can use a unibit to dril the hole or drill it small then hog it out with a diegrinder

IMHO if you cant figure out what size drill bit, then you need to take it to someone because noone wants a leaky oil pan.

 

Thread size on a -12AN fitting is 1-1/16" @ 12 threads/inch. Tap drill size is somewhere between .972"-.995" depending on thread engagement depth. Through hole should be 1.0625" nominal.

Oh, and -12 is huge for an oil return no?

 

The measurement is not the OD always, it's Tubing OD and hose ID. Much like when you refer to piping, or tubing in the plumbing world.

Also, he did say he was using a bulkhead fitting.

OP, so long as you are close enough to the OD of the thread that you get a good snug fit and proper sealing with the teflon washer you'll be fine.

The post above me gives you some good info, in the future just grab some verniers and hit the OD of the threads and you'll know where to start

 

Thanks for the response guys.