# Union 3 Jaw Chuck Question



## barnett (May 29, 2016)

I bought a 6" unknown 3-jaw chuck to put on my rotary table, $23.00 on fleabay, stated that it needed cleaned up. I disassembled and cleaned it up. It turned out to be a Union chuck. It has " class S " stamped on it. Anyone know what it means ?

It looks to me to the thru-hole has been bored out. there are 3 holes in the back that have been bored into and 3 holes thru the front. I know the 3 larger holes in  the back are for a backplate.

What are the bolt holes in the back and front for ?? dust cover ??

Any ideas are welcome !

Tom


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## Ulma Doctor (May 29, 2016)

i don't know what class s is, but you got a pretty good deal.
it appears somebody did some work to it...
the holes are for mounting spindle adapters like these


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## barnett (May 29, 2016)

Thanks Mike. The $23 was with the shipping, i only bid $10 on the chuck with$13 shipping. It was covered in junk, the inside was full of dirt, grease  and swarf. I checked it out and its still in fairly good shape inside. 

Tom


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