Quote Originally Posted by Tenson View Post
Mine has an ER16 clamping nut. I guess I can't use ER20 as the part the collet goes into (spindle shaft?) will be too small?
Yes the dimensions of the taper for ER20 are completely different so you'll have to use ER16, so upto 10mm:

http://www.ebay.co.uk/itm/FULL-ER16-...item231b785020