I think the one I had dumped in my lap was a 16x54. Used to cut a lot of weld with it, and it's let out a groan and cut the stuff like butter. Once you learn the threading part, you'll find it really turns a nice thread with very little lead error. I got it because I was looking for something surplused that had a 3.38" hole thru the spindle and still do metric threads. But the thing was huge for what it was
gary