Centering aid for polygonal stock

[Toolmaker51]

abbreviated;

Centering square stock in the 4jaw can be a trial...To deal with the square stock problem, I made a simple gizmo.

When not physically at a machine, I typically invest time in study of what work is coming up. Surfing the vast HMT content is more than entertainment.
Personally, tooling is a favored keystone to streamlining work. The 'cost' is high for the first article, diminishing with each produced. Upon re-use the cost is effectively zero.
Once again, [with equal thanks to HMT & mklotz] I have a solution for a run of link pins. Naturally, stocks larger than square collets available...Up to now, a square split bushing + 3 jaw was the only reasonable solution, and limited to one size!
Best part; they'll be concentric enough to drill for cotter pins clamped and located by the original material.
So, this accounts perfectly in my recurring "...this is not just a hobby" admonishment.