# Is There A Definitive  Article On Collets



## savarin

The title says it all.
Is there a definitive article on collets anywhere?
The information I'm after is something like:-
what are the different sizes
what are they for
different methods of holding the bits
types of lathes they are suitable for
suitability  for differing jobs etc
and any other information that may be of use to the newbie wanting to select a set.


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## JimDawson

The short answer is:  It doesn't seem that what you want exists  on the Internet.  Google Collet Types that's the best I found.


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## RJSakowski

savarin said:


> The title says it all.
> Is there a definitive article on collets anywhere?
> The information I'm after is something like:-
> what are the different sizes
> what are they for
> different methods of holding the bits
> types of lathes they are suitable for
> suitability  for differing jobs etc
> and any other information that may be of use to the newbie wanting to select a set.


Not an expert but here goes:
Collets are usually available in both SAE and metric dimensions.   SAE are typically made in fractional increments and metric in mm increments but they can be any size. Some collets are made to be custom machined by the user.  Collets also come in other geometries than round; e.g. square and hex.

Collets are used to hold work in a lathe or tools in a mill.  They hold work or tools by virtue of a taperd surface with slits which mates with a tpered socket.  As the collet is drawn into the socket, the socket collapses and grips the part or tool firmly.  Their claim to fame is their ability to hold with minimal runout.

Use on a lathe can be directly with the spindle socket as in Morse taper collets or with a collet chuck mounted to an adapter or to the spindle chuck mount. R8 collets are common on mills.

There are many different collet types.  Morse, C5, R8, and the ER series are common ones.


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## Uglydog

I've always found this helpful.
http://www.hardingeus.com/usr/pdf/collet/2351.pdf

And this article interesting, especially when I had some cheap collets & endmills that were slipping and walking.


Daryl
MN


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## David S

I have some MT2 metric collets for my lathe.  I find that these collets require the piece to me held to be the same diameter as the collet.  I.E. 12 mm collet for a 12.0 mm shank.

For the clock work that I do to hold arbors I have a set of ER collets (Extended Range).  This means a reasonable number of collets can handle a wide range of diameters..

David


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## brino

Hi Savarin,

I initially read your topic and thought "what's to know; they are collets!". But then after seeing your questions, the useful answers above and having it sit in my brain a while I realize it's not that simple......there are a number of details about mounting, size ranges, use that are definitely NOT obvious.

I have never seen a detailed guide to collets. I originally just liked the advertised concentricity and repeatability and jumped in and started buying/using them. The first set I got was ER-32 for my old lathe, then some MT4 ones for my mill, then some MT3 ones for my rotary table, and then some 5C ones for an indexer....wow, they do add up! They have been very useful, and I have a few thoughts to add...

The collets that fit directly into your spindle taper should be the most accurate as the spindle taper itself was turned on the spindle centre. Any extra taper adapters, nose-thread adapters will necessarily add more room for error and decrease repeatability; you may not get them reinstalled the same way a second time.

My big mill has a Brown and Sharpe #11 taper. I cannot find tooling in that size, but was able to find a B&S#11 to MT4 taper adapter and I can use MT4 collets in that to hold end mills.

My lathe has an MT3 spindle taper and 1-1/2 x 8tpi nose. I could use MT3 collets directly in the spindle with a draw bar to tighten....but I usually don't for two reasons:
1) the holding range of the MT3 collets is limited to small diameters

2) I dislike using the threaded drawbar.....it tightens up great, but loosening it feels so stone-age! I need to tap the end of the bar to shove the collet out of the spindle taper. I put a long coupler nut on the threaded bar to spread the force over more threads and use a soft-faced hammer...but I still hate the thought of hammering on the threads.

There are special collet closers you can add to a lathe, either handwheel or lever operated, but they necessarily reduce the maximum diameter thru the spindle.

I have found ER-32 adapters for my lathe that I really like. Beall tool makes them in the USA:
http://www.bealltool.com/
http://www.bealltool.com/products/turning/colletchuck.php
They advertise them as being for wood-working; I've never used them for wood, they work great for metal.
Their set of collet sizes are limited, but the adapter is standard ER-32 so you can buy more anywhere.
They used to offer a larger set (ER-50?) as well, but I don't see it there now.......

For me the beauty of the ER-32 collets is in overcoming those two issues above:
1) I can get and use ER-32 collets in a huge range of sizes right up to the maximum thru hole of my lathe spindle!

2) the loosening....the nut has as an off-centre ring that locks into the groove on the collets. You actually have to install the collet into the nut before putting the nut/collet onto the tapered nose adapter. http://www.bealltool.com/pdfs/collet_chuck.pdf



It is tightened and loosened with pin wrenches. That allows the collet to be pushed out of the taper when loosening. No hammer required!

Even though the more do-dads you add between the spindle and the collet the less accurate it gets the above have always met my needs.
However, if you start making pieces for NASA's next telescope, you may need to reconsider........

Jeez...this is turning into a book...I'd better sign off.
Keep having fun!
-brino


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## savarin

Thanks Brino, good one.
So would I be correct that none of the collet systems allow long lengths of material to protrude through the back or do some of the er chucks have a through hole?


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## brino

savarin,

Some collets do allow long bar stock thru them.....if either:
1) they have a nut that compresses the collet into the taper
or
2) they can use a hollow draw-bar tube

My ER-32's are of the first type. Here's a couple shots of a 3/4" collet on a bar; that's the max size that will fit thru my lathe spindle.






The adapter on the left goes onto my 1-1/2"x8tpi spindle like this:





My MT2 and MT3 collets require a 3/8"-16tpi draw bar. Since that draw-bar is such a small diameter, it is solid. That limits the gripped depth to about 1-1/2".
Yet another reason I like the ER-32's better.




The 5C collets that I use on my indexer have thru holes and are drawn in by a hollow tube that grabs the collet external threads.
So they should fit the marked size right thru up to their limit....which I'm not sure of...I know my largest is 1-1/8".



I have no R8 collets. Someone else will need to comment on those.

another book, but at least it's a picture book.........

-brino


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## savarin

Hmm, I wonder if I'm competent enough (somewhat dubious) to make the collet holder to fit my spindle.
Then if its made in place it should (should being the operative word) be spot on and I can use ER32's with a purchased nut.
If I purchased the adapter to screw onto the nose of the lathe I would assume it would not be as accurate as one made on the spindle.
Damn, another project for the future


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## brino

Uglydog said:


> And this article interesting, especially when I had some cheap collets & endmills that were slipping and walking.



Daryl,

Thanks for posting that paper on preventing collet slip. A very interesting read!

-brino


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## eeler1

Machinist handbook


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## RJSakowski

brino said:


> My ER-32's are of the first type. Here's a couple shots of a 3/4" collet on a bar; that's the max size that will fit thru my lathe spindle.
> -brino


Hey brino,  Where did you get the ER32 adapter?  Thanks.

Bob


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## Dave Smith

eeler1 said:


> Machinist handbook



You are right--- machinery handbook covers the older collets and which machines they are used on---they have all the dimentions--if you have the older lathes and mills it is a handy information chart---but the 14th edition is the last edition to cover collets---I don't understand why because collets are still used in most machines----and machinists need this information--I probably have at least twenty different types and styles of collets and holders--some I don't use but someone with an older machine with special collets might-------Dave


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## brino

RJSakowski said:


> Where did you get the ER32 adapter? Thanks. Bob



Hi Bob,

That lathe spindle nose mount for ER-32 collets came from Beall:
http://www.bealltool.com/
They are made in the USA!

Specifically, the ER-32 collet chuck for various lathe spindles are here:
http://www.bealltool.com/products/turning/colletchuck.php
I originally had their 1"-8tpi 5-collet kit for my old Barnes Lathe, then when I got the Southbend lathe I bought just the 1-1/2"x8tpi collet chuck and wrenches.
I have collected more ER-32 collets from local places and ebay, both metric and imperial.

...and hey their "Big Chuck" ER-50 version is back:
http://www.bealltool.com/products/turning/bigchuck.php
(the big one was gone last time I looked, now that it's back I may need to order one.....hmmm.......)

-brino


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## WalterC

I'm glad this question was asked. I spent a lot of time looking for this info.  
 I was looking for a 2MT to R8 adapter, so i could use the more standard R8 collets in my 2MT mill.


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## Tozguy

Savarin, it is not obvious that making your own adapter would be more precise than a purchased one. No insult, its just because the whole idea of collets is to have a more concentric hold on the work than a scroll chuck. So they are precision made and that's why they can get expensive. However, I am sure that you can do just as well making your own adapter if you are so inclined.
ER collets are the most versatile for general use in a hobby workshop. So unless you have a specific job that has special requirements I would go with the ER type for workholding in a lathe.


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## GK1918

Uglydog said:


> I've always found this helpful.
> http://www.hardingeus.com/usr/pdf/collet/2351.pdf
> 
> And this article interesting, especially when I had some cheap collets & endmills that were slipping and walking.
> 
> 
> Daryl
> MN


Thanks Daryl thats what I'm looking for because it has been said ER collets will work with the 3CH monoset system.
but I can't find out if I need ER32 or ER40???
sam


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## Uglydog

GK1918,
Sorry that's all I got. You might check the Machinerys Handbook. 
Additionally, I found this in my files. Not sure if it will help. Wish I knew which website I got it from...

Daryl
MN


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## savarin

Well I took the plunge and bought a set of metric ER25's
but I've no idea when I will be able to start on the spindle nose chuck.
Too much going on at present.


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## Tozguy

WalterC said:


> I'm glad this question was asked. I spent a lot of time looking for this info.
> I was looking for a 2MT to R8 adapter, so i could use the more standard R8 collets in my 2MT mill.


 
Walter, I looked for an MT3 to R8 adapter with no luck. The R8 taper seems too big to fit inside an MT3 and an MT2 is even smaller.
Do you have a plan B?


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## David VanNorman

You can make an adaptor to go from your spindle to the R8 But the 5C or the Er series 32 or 40 makes the nicest set up.


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## spumco

I too like the Beale, but consider it a kit.  I had to true up the taper on mine afer mounting on my lathe. Once done, it holds accurately.  As received, not so much - like out by over .003" right at the collet face.


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## Jimsehr

I can collet up to 1 3/8 stock THRU  my 11 inch Logan lathe. With my collet chuck. In fact I held my  1 3/8 5c collet tube in a collet when I made it fit my lathe.
Jimsehr


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## brino

Jimsehr said:


> I can collet up to 1 3/8 stock THRU my 11 inch Logan lathe. With my collet chuck. In fact I held my 1 3/8 5c collet tube in a collet when I made it fit my lathe.
> Jimsehr



Jimsehr,
That's huge!
What collet system is that you have on the Logan?   (ie, ER-50, or a manufacturer specific one?)

Thanks,
-brino


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## Jimsehr

brino
I have 6 or more collet chucks. Two that fit a Logan spindle 2.25 thread ,one that fits a Logan LOO spindle thread and about six more that fit different spindles. I have them that take 5c collets , 2j collets, and 3j collets . Hardinge collets. And some that take rubberflex collets  that will go thru the spindle 1 3/8 dia. The 2j collet will take 1 3/8 thru. The 3j will take 1 3/4 thru the front of collet till it hits the front of the spindle.
Some of the speed collet chucks are Hardinge-Sjogren some are Jacobs.
Yesterday there was a collet chuck on Ebay for $95 plus $25 shipping. It did not come with collets . Collets sell for new about $50 each brand new and you need 11 collets for the full set. You can get them cheaper on ebay. they go from 1/8 thru 1 3/8 rubberflex.
 MSC still carries Slogren speed collet chucks for camlock spindles collet chucks starting about $1300 and the larger ones go for more
then $2000.
But if you find one on ebay you could make your own back plate . That is what I did on the first one I use on my Logan 11 inch spindle.
jimsehr


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## David VanNorman

I like my 5C set up . I just wish I had a larger machine that I could get the through advantage of the 5C.


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## Jimsehr

Thinking about collets . They can be so much faster then a chuck . You can load and unload in seconds . If you have a spring loaded stop it can take only about 5 seconds to load and unload parts because you don’t have to stop spindle. You can use 5c step collets to hold like a 4 inch dia 1/8 thick part. You can use 5c collets to hold hex or square parts. And you can put a 5c collet in a lathe to run a part then use the same collet to hold the part in a mill or other machine to drill a hole pattern or mill a slot etc.  You can offset a bore on a soft 5c collet to turn excentric parts like cams. I have even threaded soft collets to hold on the thread pitch of parts.
And you can use ID 5c collets to hold on the bores of parts .


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## BROCKWOOD

This chart is just the basics for selecting what ER Collets might be best for you. It's just numbers from Daryl's Hardinge link above boiled down to overall size (inside the holder) & what sizes of stock you should be able to work with for each style.

*EDIT* This chart is just for metric sets. A chart that includes imperial sets is given further down (page 2 of this thread).


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## Ray C

BROCKWOOD said:


> This chart is just the basics for selecting what ER Collets might be best for you. It's just numbers from Daryl's Hardinge link above boiled down to overall size (inside the holder) & what sizes of stock you should be able to work with for each style.
> 
> View attachment 268341



Brockwood,

That's a handy reference to have but, I noticed an error in the ER 32 Row.  The US Size Range shows a max of .118 when in fact a standard US set will go up to 3/4.

Also, as a general note of consideration, most ER collet sets are offered in expanded ranges at the low and high end.   ER 40 for example, can go up to 1-1/8.

BTW:  We learn something every day.  I didn't know there was an ER 8 setup.   I bet they're cute little devils.

Ray


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## Tozguy

Here is another example of the extended range that Ray C mentioned:
ER32 collets up to 7/8ths   https://www.maritool.com/Collets-ER-Collets-ER32-Collets/c21_56_59/index.html?page=3


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## higgite

Ray C said:


> Brockwood,
> 
> That's a handy reference to have but, I noticed an error in the ER 32 Row.  The US Size Range shows a max of .118 when in fact a standard US set will go up to 3/4.


There's also an error for ER20. Max should be .512".

Tom


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## BROCKWOOD

Revised chart.  The original chart was just for metric & expected some collets to tighten down below nominal size. In this chart only min & max nominal size is given. ER8 & 12 are only available in Metric sizes. All other styles include both a metric & a imperial set.


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