# how does Morse Taper Drill Collet work?



## Ken from ontario (Jul 8, 2017)

I just saw a listing on ebay for #2 morse taper 3/8"  drill collet, the seller has many of these #2mt collets for   different sizes of drill bits and  taps. now my silly question:
I'd like to know how  well do these collets hold the matching drill bits? I'd imagine you insert the collet (with the bit in it) in the tailstock but how tight is the  tailstock  going to hold the bit  to prevent it from spinning when drilling ?
Is inserting the collet with a simple push, enough to tighten the collet around the shaft of the drill bit?


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## Silverbullet (Jul 8, 2017)

I think the bits need flats on two sides like the morse taper to lock them in . The work for taps and reamers too. I used them many years ago. They're quicker then chucking in a drill chuck. Well made for accuracy also.


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## Ken from ontario (Jul 8, 2017)

Silverbullet said:


> I think the bits need flats on two sides like the morse taper to lock them in . The work for taps and reamers too. I used them many years ago. They're quicker then chucking in a drill chuck. Well made for accuracy also.


Bit with flats on two sides would make sense but that means you can't use ordinary bits with these collets.
The actual drill bits that have tapered shanks should be quicker to put on and remove .
Thanks for the explanation  ,I was just curious to know how they worked.


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## Wreck™Wreck (Jul 8, 2017)

That is old, haven't seen one of those in years, I do currently use MT tap holders however, this is about the only way to hold a large tap in a MT machine.


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## T Bredehoft (Jul 8, 2017)

The taper is meant to keep the bit from turning. The tab on the end is generally hardened, so that a taper can be driven in the slot to eject the drill from the sleeve. This is Old School.


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## Dave Smith (Jul 8, 2017)

On a 3/8" size you just clean them good and silver solder the bit in the holder---I have sets of them of many sizes---the tang on the mt holder keeps it from spinning in the tailstock----Dave


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## Wreck™Wreck (Jul 8, 2017)

Dave Smith said:


> On a 3/8" size you just clean them good and silver solder the bit in the holder-


Really, was this a common practice?


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## Dave Smith (Jul 8, 2017)

Wreck™Wreck said:


> Really, was this a common practice?


I think it was if the holder is empty----I haven't tried heating one of the ones with a drill bit in it, but I have several holders without bits in them --I will have to look at my bits and try removing one--will get back on results----Dave


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## Bob Korves (Jul 8, 2017)

I have tried them by just sticking the drill in the holder and tapping it solidly with a dead blow hammer.  It stuck like glue, did not spin under a heavy load, reduces needed head space in a drill press or mill or lathe, and are easy to knock out with a tapered arbor remover.  I have maybe 20 of the holders in different sizes.  I rarely use them, but they sure could be.  If you have the Scully Jones (or equivalent) magic quick change holders for them, they are indeed quick change tooling.


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## Ken from ontario (Jul 8, 2017)

Bob Korves said:


> , reduces needed head space in a drill press or mill or lathe,


That's what piqued my interest , owning a mini mill and a 7x16 lathe ,I need all the extra space I could get.  recently bought a set of stubby  drill bits for the same reason. for now I'll pass on this collet deal.


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## Wreck™Wreck (Jul 8, 2017)

I know well how they hold taps in a square recess at the bottom of the holder, can not imagine how one would not spin a drill held with the taper pressure alone.

This is probably a good thing if the machine has the power and work holding to break the tool rather then  spinning the part or breaking the tang off of the taper adapter.

I often rough drill holes in round stock for finish boring in another machine with a Warner & Swasey #5 turret lathe, this machine will not stop for any reason. One may spin the taper drill breaking off the tang, the part may spin in the chuck or be pushed through, however the spindle and feed will not stop.

I can not imagine not spinning a drill with such a holder, but what do I know (-:


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## Bob Korves (Jul 8, 2017)

Wreck™Wreck said:


> I know well how they hold taps in a square recess at the bottom of the holder, can not imagine how one would not spin a drill held with the taper pressure alone.
> 
> This is probably a good thing if the machine has the power and work holding to break the tool rather then  spinning the part or breaking the tang off of the taper adapter.
> 
> ...


The drills are only held against rotation in these holders by friction, same as a drill chuck or collet, which both work pretty well.  If you have a buggered rusty drill and a rusty buggered holder socket for the drill, and you install them with a small love tap, I have no doubt they will be easy to spin.  If the drill shank is clean, dry, and the correct size, the I.D. of the holder is in good shape, not rusted or buggered or oily, and the drill and holder are driven in solidly to achieve the required friction, then they hold quite tightly.  The small MT taper angle multiplies the clamping force considerably, which increases the friction considerably, and the contact area of the holder is much larger than, say, drill chuck jaws.  I do not have a lot of experience with them, but all good so far, and it is telling that none of my holders which were bought used show damage from spinning drill shanks.  Of course, something has to give at some torque level, I would not be surprised if it was the drill flutes.  Perhaps someone else on H-M has more experience with these holders and will comment.


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## T Bredehoft (Jul 8, 2017)

I tried to say above that friction held the drills. I've seen many drills with broken tangs, the tang is soft so it will brake. The friction of the taper holds the drill, and yes, it is supposed  to be seated with a soft face hammer.


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## Wreck™Wreck (Jul 8, 2017)

Bob Korves said:


> The drills are only held against rotation in these holders by friction, same as a drill chuck or collet



Collets do not hold drills very well when pushed, drill chucks are even worse. You can't hold  a round shank drill in an R8 spindle if your life depended on it.
If really pushing a  twist drill in a lathe or drill press taper shanks work very well, if  in a mill spindle, say Cat 40 or larger there are alternatives to twist drills.


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## Silverbullet (Jul 9, 2017)

I have several of differing sizes the drills will work with or without the flats. I use them more for reaming then drilling , some are dedicated to taps in my old box.


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