Bob Swinney wrote in article
...
A 3/16 screw would have a nominal diameter of 3/16 = 0.1875 inch; whereas
a
#10 screw diameter is [ 0.060 + (10 X 0.013) ] = 0.190 inch. As you
said,
they are pretty close, about 0.0025. AFAIK, 3/16-32 is not a standard
machine screw.

Bob Swinney

A number of years ago, a machinist friend of mine gave me the formula for
numbered screws, and I lost it.

I cannot remember why I was looking for it recently, but I simply could not
find it anywhere - even in the 25th edition of Machinery's Handbook
(although I suspect it is in there and I simply wasn't looking in the right
place).

I have printed it off, and tucked it away in the "formulae" section of my
"Bob's Big Book of Stuff" looseleaf in the shop.

Sometimes, when you try to help one person, you will also help another in a
totally unrelated way. This is one of those examples.

Thank you for posting the formula here..

Bob Paulin - R.A.C.E.
Racing Chassis Analysis Services