Franklin Foundry 12 x 37

Hi svfrolic, welcome to LJ!
What lathe? Where’s the picture? Maybe a brand name? Something. We need hints.

If it’s a full size lathe, it’s a good bet the taper is #2 MT. Any friends nearby to borrow a taper to check fit?
DanK

-- Dan Krager, Olney IL http://www.kragerwoodworking.weebly.com

Perhaps you could remove the headstock’s and see if it fits the tailstock. If it does, take it with you to the store.

Another alternative is to work with a supplier that will let you buy both and return one.

Or, you could measure the diameter of the opening in your tailstock. A #1 is approximately 12 mm whereas a #2 is close to 18 mm when measuring the diameter just shy of the thickest end.

Oh yes, there’s also the MNgary method. If my pinkie finger is a nice fit it’s a number 1, but if my thumb is a nice fit it’s a #2.

-- "I dream of a world where a chicken can cross the road and no one questions its motive"' - Anne Nonny Mouse

Dan:
It is Franklin Foundry 12×37. It was sold by Sears years ago.

MNgary:
I measured it and the opening is just a little under 1/2” which would make it close to 12mm. No chance my thumb would fit there:-)

Well, there you have it. The numbers tend not to lie. It’s a good thing I didn’t bet on it, because I felt very strongly that a lathe that big would have used a larger taper.
DanK

-- Dan Krager, Olney IL http://www.kragerwoodworking.weebly.com