wrote in message
oups.com...
"Shoulder Screws" have a precisely ground cylindrical shank between the
head and the threads that is very good for locating parts.

Jim Wilkins


No, they are *not* good for locating parts. You're at the mercy of the
threads being concentric with the ground body, and that isn't guaranteed.

This job would be a classic example of how tools are built-----with the use
of dowel pins, either straight, or diamond, as Ned alluded. If exact
orientation is desired, pins can be installed such that the parts will come
together in only one way----and held together by screws of one's choosing.
Tapered pins would be a PITA in this instance, for they don't always release
without a struggle. Dowel pins, properly applied, do, and have the
potential to locate within tenths of a thousandth.

Need more info? Feel free to ask. I worked for years as a tool maker.

Harold