hello to eliminate doubts, i would suggest measuring your spindle nose you know, numbers dont lie
a quick reference :
... a2-6 has primitive diameter o133.4
... a2-8 has primitive diameter o171.4
... http://www.lathes.co.uk/spindlenose/spindlenoses.pdf ( this document may be outdated )
... post a photo with your actual chuck, and maybe i will be able to help you determine the spindle-nose, without removing the chuck
about the chuck, pls consider :
... normal and big-bore chucks : kitagawa b and bb series
... quick jaw change : kitagawa qjr and qb series
*i dont sell kitagawa; just saying ...
i would recomand you a bb or a b+qb master base jaw also be sure that the pull-bar can fit the draw nut of the chuck
If you already have a B200 series chuck then all you have to do is replace the B200 master base jaws with the QB300 master base jaws and you have a quick jaw change chuck that is 30-50% cheaper than any other Quick Jaw change chuck on the market.
full article : https://www.kitagawa.global/en/news/...ge-jaw-options
maybe you also wish for another collet chuck ?