4" Union 3-Jaw Chuck w/ 1" - 8TPI Spindle Thread?

bearbon

Registered
Registered
Joined
Mar 21, 2013
Messages
26
I was given a Union U-2148 4" 3-jaw chuck that is in very nice shape. It came with a long tapered mount (not morse taper) that was pretty rusty. When I removed I see that the chuck has a 1" - 8tpi spindle thread. It's not a removable adapter but integral with the chuck itself. Looking online the only 1"X8 chucks I find are for wood lathes, but this is obviously a metalworking chuck. I think Craftsman made lathes with that size spindle but I don't know if they were metal lathes. Of course it could be fitted with a Morse taper adapter for my South Bend but just wanted to ask if anyone has more info on this. Thanks, Bear
 
My old Cushman Chuck catalog has that same chuck listed, or pretty close to it. It was common for them to make the smaller chucks with integral back plate to fit the common 1"-8, 1-1/2-8, 2-1/4-8, and 2-3/8-8 threads back then.
I couldn't tell you if there is meat in there to open up the threads to 1-1/2"-8, it could be possible.
 
The craftsman/ Atlas 6" metal lathe, started with a 1" X 8TPI chuck, and later switched to the 1" X 10 TPI. IIRC, Union is who made the chucks for them.
 
Thanks for that info. I did find that the Craftsman / Atlas 6" lathe used this thread but it's helpful to know the thread size changed on later machines. Thanks guys. This will help when I list it on eBay.
 
Back
Top