Can a Chrome Steel hardened Ball Bearing be tempered enough to milled or
drilled?

Some sources suggest heating to a RED temperature, no higher, and then
gradually cooled in fine wood ash or similar. Does this ring true with
any knowledgable folk here?

I am trying to form a branch puller for large diameter copper pipe. I'd
need to cut the 4" ball bearing in half and mill it to the right diameter
needed.

varocketry AT hotmail dotcom