Brand new drill chuck capacity range 0.5 to 6.5mm.
You can select the thread size WW standard american fit most all 8mm lathes such as:
Bergeon, Levin, Derbyshire, Boley, American Watch Tool Co., Peerless, Marshall, and most others.
Or metric size M7 x 0.75 such as Vector and HOROTEC German brand. Please check my store for other parts.