On Aug 14, 2:57 am, Tim Wescott wrote:
Certainly with pipe
threads the hole is straight and the pipe is tapered. --
Tim Wescott

Usually, but that is the quick and dirty method. The proper way is to
first taper the hole, and there are taper reamers made for just that
purpose. Most don't bother, and the taper gets cut by the tap itself.

John Martin