Pie Jaw chucks

I think you are looking at soft jaws. Soft jaws are often used on cnc lathes to hold parts. The jaws are clamped on a ring to keep them from fully closing and the profile of the part is cut into them.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Which website? Did you find a web site which mirrors this usenet newsgroup rec.crafts.metalworking? Normally, there are (and should be) no images here.

It depends. There are "soft" pie jaws which can be machined to fit a specific workpiece. But there are also hard jaws -- multiple steps which are a precise fit for standard diameters and a pretty good fit for in between sizes.

Again -- which pic? And what do you mean by "radial profile"? pie shape of the jaws, or the radiused gripping surface?

The pie shape is so when fitted to a six-jaw chuck, the chuck can be closed to the maximum amount, allowing the sides of the jaws to just barely touch.

The radial profile is to fit standard diameters -- and grip fairly well diameters just a little smaller.

Are what you saw for six-jawed chucks? The combination of the six jaws and the curved gripping surface allows gripping rings with minimal distortion compared to the same thin walled object gripped by a three-jaw chuck.

Enjoy, DoN.

Cheers Wes, I neglected to post the link to the website (my apologies!). Yeah they look like they might be soft jaws, but ones that provide more support around the part.