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The stock plate used some 1/4-20 allen-head screws in counterbored recesses.
I wanted to duplicate that, but generally, I'll use a 3/8" endmill to cut the counterbores.
These older screws (the lathe was made in 1956) must have a slightly larger head, so a
3/8" bore wouldn't fit- close, but not quite.

I rooted through my stash of old, dull and "spun in the chuck" drills and found one that
measured .400" or so- plenty of room for the bolt heads, and very close to the original counterbore size.
To make it a counterbore (and not just a drill) I ground the tip flat and resharpened it.





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