[P.W.]

I am running a Comet MV6 CNC Mill with an NMTB 40 Spindle, with a Pneumatic Power-Drawbar, and I'm in need of a lot of tool-holders, I can't get all new tool-holders, (I'm triing to get to be using mostly tool-holders with ER40 Collets) and the NMTB are not all that Common at the Auctions, but the Cat 40 are very common, so my question is, is there a possibility to change the Power-Drawbar to a Cat 40, and then use the Cat 40 tool-holders? or is the interior of the NMTB 40 spindle manufactured so different that a Cat 40 wouldn't work?

[DareBee]

The power drawbar is likely a threaded "spinner" (Usually is with NMTB)?
All you need to do is make the thread about an inch longer to use Cat.
Look at the holders side by side, you will see.
If you change the drawbar to metric, you could use BT

[P.W.]

Thank You (DareBee), I had thought about that too, I gues that would be easier and more cost effective than than the other way around.