If it's a NPT, then 1/4 I'd say. I have a 1/8 thread tap here and it's not that -- too small. Hole and thread is similar size to 1/2 UNF ( which I thought it was ) So we'll go with 1/4 NPT. Thanks.
A 1/8" regular tap is MUCH TOO SMALL. A 1/8" NPT tap is almost a 1/4" in a regular tap. I'm in the process of re-building 4 "Nails" now & they are ALL 1/8" NPT. Tom T.
You're right Tom. I had another ( very close ) look at my tap and with the help of my + 4 seeing eye dog glasses found out it is in fact a 1/8" BSPT not NPT ! And with the help of a Google thread chart found the difference. So 1/8" NPT it is. How could we have ever doubted your expertise. :TU: I will tap out the holes then it's off to the machine shop ( finally )
