When I am looking at ballscrews I see mostly metric ones out there so
please tell me about the numbers.

1. What do the numbers mean?

For example:

C3 6-1mm L145

I am guessing 6 is the diameter, and 1 is the pitch. L145 is probably
the overal length including machining.

What is the C3 or C7 at the begining? Grade? Hardness? Precision of
grind?



2. Can you clamp them up in a lathe to redo or cut your own maching
on the end? Will that bugger up the grooves? How hard can you clamp
them up? Is that going to vary from screw to screw?