Assures Correct Head/Tail Stock Alignment
Precision-ground and hardened "buttons" help ensure correct
lathe alignment, quickly. Move head and tailstock together with
buttons be- tween centers until button faces touch. If O.D. over
button joint measures .900", (nominal button O.D.) head and
tailstock are aligned. If not, the buttons are offset, and so are
your headstock and tailstock. Make adjustments and re-measure.
Big Book Catalog, Issue:65, Page:464
SPECS: Steel. .560" (14.2mm) long x .900" (22.9mm)
diameter.