Size drill bit for screw in poultry nipple?

[Quackter]

Hello!

I was wondering... What size drill bit do you use for a screw in poultry nipple? Is it a 11/32 or a 23/64? Also, should tape be wrapped around the screw part before inserted into the PVC pipe? Any suggestions you have are welcome!

Thanks!
Chantele

Hi know this is an old post, but this is the link I found on a google search. The nipples I found, red plastic, Ebay and Rural King sell them. To the best of my shade tree fabbercobblin abilities. They are a 10mm-1 thread, 9.1mm drill bit, which a 23/64, or even a 11/32 should work beautiful in plastic. 10-1 thread is typically a taper "pipe" thread, oddly the threads on the nipples are a straight seated fitting, however the tapered tap works just fine because the soft plastic nipples conform to the harder pvc.