What type of collet is this?

[Sonic EscapeParticipant @sonicescape38234]

I found a box with 36 collets at a reasonable price. I was thinking to make an MT5 collet holder for them. But from the seller pictures I didn’t realized how large they are. Anybody knows what kind of collets are this? It is not R8 or 5C.

 

[Sonic EscapeParticipant @sonicescape38234]

Actually is very close to 5C. For example thread diameter is 1.17″ comparing with 1.24″ from 5C. And body diameter is 1.26″ vs 1.24″. But the total length is 4.1″ vs 3 9/32 “. So I think this makes them 5C collets?

 

[Dave HalfordParticipant @davehalford22513]

Decent ones normally have the type engraved on the, all my Crawford 4C are marked 4C and CC for Crawford Collet.

[bernard towersParticipant @bernardtowers37738]

possibly 1AM

[peak4Participant @peak4]

The overall length seems to preclude 5C.
One possibility, if other dimensions concur, would be to get one of the square or hex 5C collet blocks & nut, then adapt to suit; it could then be used in a 3 or 4 jaw chuck.
Here’s a few hyperlinks from my bookmarks with various collet dimensions to compare;

https://lrak.net/wiki/Collet_Dimensions.html

https://www.lathes.co.uk/crawford-collets/

COLLETS 101

https://tools-n-gizmos.com/specs/C_Collet.html

And lastly from Wayback machine, an old Crawford catalogue

https://web.archive.org/web/20151129173145/http://www.600uk.com/data/downloads/products/Crawford%20Collets%20catalogue.pdf

Bill

[Dave Halford]

On Dave Halford Said:

Decent ones normally have the type engraved on the, all my Crawford 4C are marked 4C and CC for Crawford Collet.

Apologies they are marked with the Crawford part number for 4C on the face as well as the size

[Sonic EscapeParticipant @sonicescape38234]

I didn’t knew that there are so many collet models! I looks like everybody just invented one more type just like Linux distributions 🙂

Mine are indeed very close to 1AM. Or to 5C except the length. Anyway in the end it doesn’t matter. If I will ever use them I will make a collet holder for them.

[Howard LewisParticipant @howardlewis46836]

You might find that the thgread on the end is British Standard Brass!

I bought some (as part of a kit of Bell Chucks) and found that, when I wanted to make an adaptor for the drawbar to pull them into the holder.

The keyway to prevent rotation when tightening is shallow, and probably 3 mm or maybe 1/8″ wide.

Howard

[bernard towersParticipant @bernardtowers37738]

Why bother when you have a freely available and perfectly adequate system called ER where collets abound and if you’ve a mind there are taper shafts straight shafts all at to be honest ridiculous prices?

[JasonBModerator @jasonb]

Holding short work for one if you want a reason to bother. That is why I like my 5C, can hold a 1/32″ (0.8mm) length without crushing the back end of the collet. And I can’t be bothered to make a plug for the other end.

[bernard towers]

On bernard towers Said:

Why bother when you have a freely available and perfectly adequate system called ER where collets abound and if you’ve a mind there are taper shafts straight shafts all at to be honest ridiculous prices?

Can you get ER series in square or hex?

Bill

[old martParticipant @oldmart]

I failed to find a match in the Crawford catalogue, the thread could be 1 3/16″ or 30mm. Checking the thread pitch might narrow it down.

You do have enough to make it worthwhile making a holder, maybe from a steel bar which could be held in a 4 jaw chuck, or part of a plate which could be bolted to a chuck backplate.

It was common for markings to be on the nose of collets, it might still be visible on the least used of them.

They look like our Smart & Brown 2802 collets on steroids.

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