CHUCK Name

[Speedy Builder5Participant @speedybuilder5]

What do you call this type of chuck please

Bob

[bernard towersParticipant @bernardtowers37738]

Extended jaw chuck/ Grinding chuck???

[old martParticipant @oldmart]

Looks like six jaws, the normal use is for holding twist drills for grinding. The very long jaws support the drill far better than normal length ones.

[old mart]

On old mart Said:

Looks like six jaws, the normal use is for holding twist drills for grinding. The very long jaws support the drill far better than normal length ones.

Yes, that’s what it looks like? The full image.

[Chris CrewParticipant @chriscrew66644]

Six jaw chucks are used when holding thin-walled work pieces where a more uniform holding pressure reduces the risk of distortion.

[Vic]

On Vic Said:

Yes, that’s what it looks like? The full image.

 

Please cite or give a link to the source of the image.

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Anyone care to speculate concerning the numbers on the backplate?

There is an indexing pin, numbers and holes at the handwheel end of the item, but I cannot see the purpose of the ones at the chuck end.

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Sanou make six jaw chucks supplied with long jaws if a chuck alone is required. I have only ever seen that style of jaws on a six jaw chuck.

It would be possible to buy a chuck that uses two piece jaws and make top jaws to any pattern. There are two common (and standardised) styles: serrated and tenon; it is a lot easier to make jaws for the tenon-style.

[JasonBModerator @jasonb]

DC31K said

 

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I have only ever seen that style of jaws on a six jaw chuck.

Have you got an image? All the six jaw lathe chucks I have seen have stepped jaws not the plain slope that the OP is asking about.

Grinding chucks being made to grip the external shank of tools do not need the steps

[Speedy Builder5Participant @speedybuilder5]

Sorry,  the image was a screen grab from Alixxxxxx.  Jason’s image/supplier is what I was thinking about, but not at that price.

On a previous post,

GRAVOGRAPH AF3

I said that I had acquired what appears to be a ‘D’ bit grinder, and am looking into the possibility of turning it into a Drill bit grinder.  I could use an ER collet chuck perhaps, or look out for a set of collets, but there would be limitations on max/min drill diameters hence search for a small chuck with long nosed jaws.  Perhaps ordinary jaws would give sufficient clearance between wheel and jaws.

The Gravograph machine does not allow for putting a rake angle onto a drill bit, but I have a cunning plan whereby the whole head can be advanced by use of a home made cam. I will see what can be done here first.

Bob

[Howard LewisParticipant @howardlewis46836]

If the base could be mounted on a 31 degree wedge, it could be used to grind drills, by passing across the face of the wheel.

My Worden does this in a similar manner, as do other cutter grinders.

(Would need careful setting up to the initial Zero clearance angle)

Properly ground four facet drills cut well and accurately, so it might be worth the effort to make the fittings for this.

Howard

[John HinkleyParticipant @johnhinkley26699]

For what it’s worth, I bought a Sanou six jaw chuck for my 9 x 20 Asian lathe quite a few years ago. It was a 125mm diameter one with stepped jaws. In the same advert, if you selected the 100mm diameter version, you could only get one with sloping jaws as shown in Vic’s photo.

John

Edited to correct my defective memory.

 

[peak4Participant @peak4]

A few extra photos on this advert from Amazon, where you can see the cam ring better

The description specifically refers to drill grinding; I assume the pegs slide up and down the cam/ramps, and are positioned according to the number of flutes. (I have 3 & 4 flute core drills.)

I have a similar, but much simpler item, where there are only two ramps, which are internal.
I’ve been looking for something similar, with instructions.
No brand name on mine, so it may have been made on a toolroom as a one-off.
When I bought it as a speculative purchase, I wondered if it might be designed for making two flute countersink bits.
It came without any means to hold a drill/mill, but I’ve temporarily used an adapted ER25 chuck I had spare.
I was eventually going to get on of the Sanou K13 II chucks with extended jaws, once I’d perfected how to use the gizmo on ER25.

Bill

[JasonB]

On JasonB Said:

Have you got an image?

Maybe what I wrote was open to misinterpretation. Perhaps it would be more accurate to say that I have not seen a three or four jaw chuck with that style of jaws (because they do not need that style), only six jaw chucks that are used for grinding as you say.

The OP was seeking a name for the chuck – I was trying to highlight that whatever the name, it would only be available in a jaw count of 6.

As above, the Sanou one is K13, often seen with a -100 suffix, the 100 being the diameter.

[peak4Participant @peak4]

As far as Sanou are concerned, I can’t speak for other makers, it seems that they only make a sloping jaw chuck in 6 jaw SC format.
K10~2jaw Self Centring; K11~3 jaw SC; K12~4Jaw Self Centring; K13~6 Jaw SC

Hence in my previous post I mentioned K13 II, where the II refers to the sloping jaw variant, which looks like it’s only available in 6 jaw SC

The lathe chuck catalogue is HERE, N.B. that’s a direct link to a PDF download, see P32

Bill

[old martParticipant @oldmart]

I bought a 160mm six jaw with two piece jaws on an Di3 backplate for around £150, taking a big chance because it was Vevor branded. I sold the backplate for £40 and at £110 the chuck is outstanding in accuracy at any diameter and just as good with the jaw tops reversed. Better than 0.002″ tir whatever size being held and I have some helicopter roller bearing races from 2″ to  7″ diameter to check larger sizes enabling holding on the outside of the inside jaws in addition to inside holding. It has the standard profile jaws, not the very fine ones in the pictures and can only hold diameters above 6mm, but I would use an 80mm TOS for little things. The only drawback that I found is that it takes a long time to unscrew and screw up 12 SHCS, but did find to my surprise that the jaw pairs have unique serial numbers to keep them paired.

[Speedy Builder5]

On 28 August 2026 at 20:11 Speedy Builder5 Said:

What do you call this type of chuck please

Bob

 

Charles?

Sorry couldn’t resist 🙂

[John HinkleyParticipant @johnhinkley26699]

Well, if we’re in silly mode, I would have thought that its Latin name would be more appropriate:

“Agrippa”.

John

 

[gerry maddenParticipant @gerrymadden53711]

I first recall many years ago seeing a six-jaw chuck fitted to a Japanese precision lathe. It was being used in connection with an industrial competition to form the deepest hole in a fine propelling-pencil lead. Some may think this silly, but the Japanese took it very seriously, of course.

[Author]

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