Atlas 10" Lathe chuck question.

[Atlas2start]

I was checking my Atlas 10 lathe tooling, and found that what I thought was a 5" medium duty universal chuck No. U-435. Upon closer inspection, it says 6612. I thought I had a chuck for an Atlas 6" lathe by mistake, but it fits on my 10" lathe. And it is an Atlas chuck. What do I have here?

 

[pontiac428]

Looks to me like you have a nice 5" chuck with internal and external jaw sets. I doubt you will run out of capacity with that chuck on an atlas. You can't put a 10" chuck on a 10" swing lathe, you won't be able to open the jaws without hitting your bed ways. 5" and 6" chucks are the sweet spot for your lathe, and that looks like a good one.

 

[wa5cab]

Sometime between 1952 and 1958, Atlas must have changed chuck vendors. In a 1958 catalog, the 6612 is shown as a 5" 3-jaw medium duty chuck with 1-1/2"-8 threads.

Many of their accessories had part numbers in the 6000 range. 6612 is a 6" dia. 3-jaw with 1-1/2"-8 threads and 6611 is a 4" 3-jaw with 1"-10 threads. In other words, the part-number beginning with a "6" had nothing to do with the lathe size.

 

[Atlas2start]

Thank-you for that information. I thought it was the correct chuck for the lathe, but its good to have confirmation.