threaded spindle

This "threaded spindle nose" type of mounting was the typical method in the 19th century through 1930s.

A drill chuck may have a hollow body that threads directly onto a lathe's threaded spindle nose.

These resemble C-clamps in that a long, threaded spindle passes through the end of the clamp's lower jaw and is used for tightening the clamp.

The exact-adjust (Set-Tru) concept is one way to chase high concentricity on threaded spindle noses with some relative degree of ease.