I'm trying to decide the correct drill bit size for a hole I have to make to fit my thread.
I measure the (major) diameter of the threaded section as 0.5325 inches. The threads are not supposed to go into the plastic.
I looked at the chart provided by Bosch, and assuming I have a 9/16 thread, the drill bit size should be 31/64. I tried 31/64 drill bit and drilled a test hole to see if it fits and it did not. I don't have 33/64 bit, but I tried 1/2 inch and it barely fits.
What is the correct method to determine the drill bit size from the measured threaded diameter? Also, since I am drilling into plastic, what is the correct way to determine the correct pilot hole drill bit?