The female thread on the adapter is an M8-1.25, while the male side is a 5/8″-16 thread. The pitches of these threads are very close to each other — only 0.0063″, or 161 microns.

Ball screws use circular or ogival (Gothic arch) threads. The nut has the same thread, letting ball bearings fit between the two grooves to transmit force and relative motion. Efficiencies range ...