I would like to have a 4-C dead center. I would also like a known near
perfect 1/2 or 5/8 collet. The collets I have are accurate near the
headstock but long rods wave around in the breeze when checked 6
inches from the collet. I have an old S.A. Potter lathe that uses 4C.
I have checked the spindle, and it is amazingly close, considering the
age of the machine. However, old collets (all of mine) are
treacherous. A known good 1/2 or 5/8 collet would be useful in holding
tooling.

Brownnsharp