Flat Head Screw Standards
Flat Head Screw Standards
(OP)
Are there anyother common specs for #2 screws other than ASMI? I have a part with a hole spec'd for a #2 flat head counterbore and the diameter is .155?
Thanks,
Rodney
Thanks,
Rodney





RE: Flat Head Screw Standards
You meant countersink, right?
The ANSI standard is for a maximum theoretical sharp diameter of .172" and a minimum edge of .146". This differs from the metric standard in which the head height is significant, and the diameter is to the outside edge. I have a 1941 drafting book , Engineering Drawing, by Thomas E. French, which quotes a head diameter of .164" without tolerance, for something called American Standard.
Is it possible that your original drafter measured an available screw?
JHG
RE: Flat Head Screw Standards
Thanks,
Rodney
RE: Flat Head Screw Standards
http://www.spstech.com/unbrako/htm/unbrakodl.html