What is this MT2 item used for?

"Waynemak" wrote: (clip) Not sure what it holds any help would be great. (clip) I use them quite a bit (pun intended.) You slip the non-tapered bore over the non-business end of a drill bit, and you now have the equivalent of a Mores taper drill, which will fit in your tailstock, or your headstock spindle.

I'd suggest they are much like a collet. A shank of a give size is inserted, then the taper is rammed in place. That drives the cutting tool of choice, and it's extracted from the taper socket via the rectangular access hole through the side of the adapter. Sort of a quick change.

Harold

Those collets are made to hold a straight shank drill with flats on the extteme end of the drill, but a regular drill will work too but it can slip a lot easier without the flats.

Also some of those type collets are made to hold taps too. They have a cutout to hold the square end of the back of the tap.

Wayne I also found a good number of MT2 drills that have coolent holes how the do they make those?

They predrill the holes and then twist the metal. Then grind and shape as necessary.

Bob AZ

Is it possible the square cross-hole is to engage the driving tang on the ends of tang-shaft drill bits? That's what it looks like to my novice eyes.

- Michael

I agree, I think it could be used as it is, but do think a tang would help lock the tool.

They either hold reamers (with their flat end) or taps (with their square end).

Nick

You're obviously correct, and I should have so noted. I have a few of the drills that are used in such adapters, though I've never used them.

Harold

Had a browse through some old catalogues and this appears to be a collet for using taps in a MT drill spindle, such tapping collets were marketed under the brand, "Ever-Wear"

Tom

I was given a full set of both drill and tap MT2 collets by an old machinist. He explained to me..that the square hole was to stick in a bit of key stock in case the drill slipped too deeply in the collet..IE to prevent the drill from moving, and to assist in removing a drill bit, perhaps one that was a smidge oversized or galled,

I use them regularly on my Hardinge lathes, and have only had one slip, due to incompetence on my part.

Gunner

Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry

It's clear the slot has multiple uses----it need not be used as a drive--no more so than a standard taper when a tang is not a part of a shank. Great design---capable of multiple usage. How many of us have seen a tang twisted off a large twist drill? They work, but only to a point. On small stuff, it insures a breakage when things go pear shaped.

It might be noteworthy than shanks on taps are generally a bastard size, even when getting to larger diameters. It's always been a source of irritation for me. :-(

Harold

Possibly, depending on the diameter of the hole. I can't help but think the concept has been used broadly, but not in recent history.

I've commented on tap shank sizes in my other post. That would help determine the intended use of the adapter.

Thanks for the info, Tom. We can always count on you for the facts.

Harold

You didn't mention what size they were, but I bet if you checked they're probably all sized to fit standard centerdrill sizes.

Jim

Ye of little faith, Harold! :-) I checked a later cat, 1937, as against 1923 and Scully-Jones were making them up to 6MT with an internal square of 1.575" to accommodate 2-1/2" taps. They listed 53 different sizes and were prepared to supply specials for specific shanks & squares.

Tom

Chuckle! And here I thought they weren't *modern!*

Harold

Along with a myriad of other standard and bastard sizes. These things represent what, today, are quick change devices.

Harold