Drill chuck capacity range 0.15 to
4.0mm with adapter for 8mm watchmaker lathe.
Please
select option list for thread sizes available.
WW standard american 0.275 x 40 fit most all 8mm lathes such as: Bergeon, Levin, Derbyshire, Boley, American Watch Tool Co., Peerless, Marshall, and most others.
And metric size M7 x 0.75 such as Vector and HOROTEC German brand. Please check my store for other parts.