Milling a 4-jaw chuck??

[modelman]

Okay machinist, I need some help. I bought a 4-jaw chuck for my lathe since I need to turn round ends on some .125" square shaft. The chuck will only close to .250". Could the angled sides of the jaws be milled down to make the jaws move further in or are they hardened? I ran a file across the edge and it cut but I'm not sure if they are hardened.

[mtloperator]

If you cut them with a file you can mill them with a cold carbide cutter . If 2 piece you'll need to do both . The best solution would be a square collet if you have a collet chuck or nose .

[doodlebug]

Make some shims for the stock and fill in the gap with them!
Don't mess the jaws up!
Cheers, Neil.

[Ken Orme]

I agree with Doodlebug.

Chucks are expenive. Use shims.

[Finster]

Perhaps you can machine a set of replacement soft jaws yourself?

[Ken Orme]

Originally Posted by modelman

Okay machinist, I need some help. I bought a 4-jaw chuck for my lathe since I need to turn round ends on some .125" square shaft. The chuck will only close to .250". Could the angled sides of the jaws be milled down to make the jaws move further in or are they hardened? I ran a file across the edge and it cut but I'm not sure if they are hardened.

How big is the chuck.

I have used penies for shims.

[modelman]

Originally Posted by doodlebug

Make some shims for the stock and fill in the gap with them!
Don't mess the jaws up!
Cheers, Neil.

Originally Posted by Ken Orme

I agree with Doodlebug.

Chucks are expenive. Use shims.

I agree-chucks are expensive!!! That's why I think using shims is a terrible idea. I have 12 ends to round and that would require a lot of set-up time. For what I paid for this I want to use it as it was intended. It is a 6" dia chuck and I actually need a 5' dia. so I think I will send it back and buy a 5" that will close to .125" if I can find it and so far I have not.