6 jaw chuck - why?

I have noticed on a few YouTube vids people using a 6 jaw chuck

I am curious as to the advantage of this

Far more support to the workpiece. More jaw less gap. Collets are better still.

regards Martin

Good holding power for precision work on bigger lathes with high cutting forces. But if the stock is a bit out of round or rough, a three-jaw will often give better grip. You absolutely don't need a six jaw chuck on the average hobby lathe.

When I was on the handles we only used 4 jaw chucks for big work where large depth of cut/high feed was used, 3 jaw chucks were occasionally used for light work and capstans for round and hex repetition stuff. The 120" chuck on the Webster & Bennett vertical borer that they had only used 4 jaws or the chuck was used as a faceplate.

I can't remember seeing 6 jaws in the UK workshops I've been in and as Hopper says they are only really any use for good symetrical stock if they work on the scroll mechanism that most 3 jaw chucks have.

Edited By Henry Brown on 23/03/2023 10:52:39

Thanks, like i say, it was just out of interest, not going to buy one

Our mechanical workshop has several. They are particularly useful for reducing distortion when holding bored out components with thin walls. Chuck a bit of tube in a 3 jaw and bore it. When it comes off the machine the bore will be trilobite to a degree.

regards Martin

I use one for the opposite reasons given above, they are ideal for turning large diameter rings that are of thin section. Much better than a 4 jaw at holding shape.

I was given an old stock, unused Pratt Burnered 6 jaw with five sets of jaws all different. It must have cost a fortune. I would not buy one for the amount of work that it has done. But is very useful when needed.

Andrew.

Edited By Andrew Tinsley on 23/03/2023 12:04:05

I thought that was exactly what I said?

regards Martin

How do you make an extinct arthropod out of a bit of tube?

Not only that but an educated one too. I obviously meant Tri-lobate. Blasted auto correct , at it again.

😵‍💫

Sedimentary my dear Robert.

The drill sharpening device one my Clarkson Tool and Cutter grinder has a 6 jaw chuck to accurately hold all the drill sizes within its range. 6 jaws are needed to retain concentricity when gripping on teh webs. The sharpener rotates to generate the drill point so, presumably this geometry requires the drill point to be concentric to the rotation axis regardless of size. A simple Vee trough and top clamp will hold a goodly range of sizes but the point height must vary with size.

Clive

Edited By Clive Foster on 23/03/2023 14:05:01

Without going into the pro's n con's you find on youtube on creator fits a 6 jaw chuck then other do bit like when someone put a steering wheel on their mill everyone got on the band wagon

H

+1 on what Harry says - afraid it's the nature of the beast that is Youtube.

Rob

Rotagrip lists them as a drill grinding chuck.

I notice Stefan Gotteswinter uses a 6 jaw chuck, he doesn’t seem to be a man who would not have a very good reason to use one when required.
Mike

The six jaw chucks intended for holding drills have very thin teeth as they are then able to grip smaller drills. The type with conventional jaws work well with thin wall tubes as already mentioned, quicker than machining special soft jaws to reduce the distortion with a three jaw chuck. The cheap six jawed chucks only have internal jaws, and the high end ones with both sets cost an arm and a leg, one reason why I have never bought one. They can suffer the same shortcomings as self centralising four jaw chucks, if the workpiece is a perfect cylinder, the clamping will vary and if the workpiece is not a perfect cylinder the same happens, something not present in a three jaw chuck.

Yep ! six jaw on drill grinders, though early Brierleys had 4 Jaw ! Noel.

Thanks Old Mart,

Now I know what the very slim set of jaws are for. It had puzzled me for years!

Andrew.

Thanks Old Mart,

Now I know what the very slim set of jaws are for. It had puzzled me for years!

Andrew.

Cutwel used to list an eight jaw chuck on their website.