I lost the little ball-bearing tip for the dial gauge. (It vibrated off and
disappeared while I was chamfering a sharp corner on the cut-down framing
triangle with the grinding wheel - shoulda done that FIRST before mounting
the dial gauge.) Spent an hour cleaning my shop, but it didn't turn up.

For a replacement, I found a machine screw with the same thread,  ground it
down to a conical end with very slight rounding at the tip, then zeroed it
out on the gauge and locked it in place with a nut.

This turned out to be an improvement over the original tip: it's MUCH easier
to measure tip rails, especially the tip rail corners to assure symmetry,
with this sharper tip.

Barry