Thanks, Jim. I have some various NMTB tooling for another mill and I tried to insert it in the spindle on the Tree 310. Even when I took the nut off, the outside diameter of the flange was too big to work with it. I believe this is an Erickson 30 QC spindle, but I'll have to try to find some brand name Erickson, Kennametal, or Valenite tool holders... the one's I've seen are pricey...

Smitty