This becomes painfully apparent in the larger taper and drill sizes:
If a #4 or #5 MT slips when driving a large drill the tang is easily
sheared off. With a #3 MT it depends on the type of tool. With # 2
MT and smaller the tang generally is of sufficient strength to drive
the tool in case of slippage.

Wolfgang,

Thanks for the heads up and info. I've never heard of a MT4+ shearing the
tang off, but I suppose it is possible now that you say it...

One of the options I offer is a MT2 with a draw bar... I suppose the draw
bar makes the MT2 seat better even if imperfect... But the clenaliness of
the tapered surfaces is always a major concern for us. Acetone is what we
use but even that leaves a slight sheen of oil. (don't beleive me? Go clean
a mirror with it...)

I'm looking to do a through-the-coolant application where the MT tooling
goes into a spindle that has a draw bar-like knock-out passageway to remove
the tapered tooling... And thus the tooling's tang will not have a slot to
knock it out because the liquid would escape!

We had a drill press here a few years ago with a MT2 tang that was seated so
well, we bent the spindle trying to remove it and ruined the drill press.
Simply deformed the drifts into mangled pieces of steel.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Flagship Site: http://www.Drill-N-Tap.com

V8013-R