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.