Michael,

In light of your answer to Ed’s question, my perception of this item is shifting
from “Rivet Set” toward “Machinery Part,” even though I did see a response from
another Porch dweller that indicated he also thought it was a Rivet Set. If that
member is positive, then what follows is probably just wrong.

The technique of locking a machine part onto a shaft with an off-center cross-
drilled pin is well known.  A taper reamer is often used to taper the cross-hole
such that a tapered pin can be backed out to release the parts.  (There are
standards for tapered pins in Machinery’s Handbook.)

If the small hole is slightly tapered and the large hole isn’t, then it’s not a
Rivet Set, but rather a machinery part.

The holes are rather large for a Rivet Set, to begin with.

John Ruth