In article .com,
wrote:
"Shoulder Screws" have a precisely ground cylindrical shank between the
head and the threads that is very good for locating parts.

But they don't always have the cylindrical part truly concentric
with the threads -- at least based on my experience using two of them to
allow a stack of parts to slide together.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---