Dimensions of Hardinge threaded spindle noses?

I'm needing to buy a chuck or backplate for a Hardinge split bed lathe with a threaded spindle nose. Figured that should be easy. Not. I find there's at least two, C-24D and C-27D. Any others?

So I look for dimensions, hardinge threaded spindle nose dimensions, but all Google and friends will give me is taper spindle nose dimensions because of course I really must have meant to type taper instead of threaded.

Anyone have a chart or something for all the various spindle noses Hardinge has used?

I'd measure it with a thread pitch gauge and a caliper.

The spindles for 5C collets have a 2 3/16-10 thread and the spindles for 4C collets have a 1 5/8-10 thread. Hardinge still sells all sorts of spindle nose tooling for 5C spindles with a choice of 4 degree taper or 2 3/16-10 thread. The 1 5/8-10 stuff for 4C spindles has not been available new for decades, but I have some. If you have a 3C threeaded spindle, I have never seen one and do not recall the thread spec.

Threaded fixture plates for 5C (plain face) are C23D, C24D and C25D. Threaded face plates for 5C (tapped and T-slotted) are C26D and C27D.

The major chuck makers used to list 2 3/16-10 threaded adapter plates for their 5" and 6" jaw chucks, and probably still do. I think I have a spare threaded adapter for a Buck or Pratt Burnerd 6" adjustable 3 or 6 jaw chuck.

Larry

The difference between C-24D and C-27D is the plate style and overall diameter, not the nose mount.

Larry,
What do you have available for the 4c spindle nose mounts or anything for 49-xxxxx 4c turret lathes?
Thank you for reading (an old thread)
J.