Jon Anderson wrote:

If you're using the stud I think you are, the hole diameter is pretty
important. It should have a shoulder that is knurled, and below that, a
circular dovetail-like feature. The shoulder cold forms material into
this dovetail for pull out resistance, while the knurl keeps it from
rotating. If the hole is even a few thou too big, the stud won't hold
securely. You want the smaller diameter to -just- fit the hole.


The original poster didn't mention what material the stud is being pressed into. I can
say from experience, if it is cast iron, hole size is critical to avoid cracking issues.

Wes