Which milling cutter shank for ER collets

I have a set of Vertex ER25 collets and holder that came with my mill.

I guess I should not use threaded shank cutters, but is it OK to use straight shank cutters that have a flat also?

It seems threaded shank cutters are more common. Should I not use ER collets and get a threaded shank tool holder?

Thanks

Adrian

Hello Adrian, you should have no problems with threaded (Autolock) cutters or the ones with a flat on them although these MAY cause the cutter to run out.

Whatever type of cutter, just make sure that there is plenty of shank being gripped and the the ER collets are tight.

Brian

I do fit the threaded shanks but I try to get the collet to hold on as much plain shank as possible, if it is the whistle notch type shank I try to get the notch away from the ends of the collet near centre if possible. This is just what feels right to me and I have not had any problems. Obviously the very best solution is a plain shank. What I do may be a big no no from the manufacturers but things have been ok so far.

Mike

I often use threaded shank end mills or slot drills in my ER chucks without any problems, just remember that the nuts on ER chucks need to be tightened with a fairly high torque.

Thor

I've got a number of Clarkson style chucks for threaded cutters so never needed to use ER collets with them. However, I do use ER collets with Weldon style cutters with no problem.

From a commercial stance threaded milling cutters are mostly obsolete and plain shank cutters rule. I've never seen a Clarkson style holder in an autochanger, which could be a problem for industry. My Clarkson holders are infrequently used for medium size cutters, 3/4" and upwards.

Andrew

Thanks guys, that makes things clear.

I have an Osborne Titanic, I think I have used it once.

The disadvantage is in the name, it's enormous and at least twice the headroom of an ER chuck.

Neil