"robert bowman" wrote in message
...
Steve W. wrote:

Wonder how a production screw machine would do cutting solid copper?

Probably better than lead. I've never turned lead, but trying to drill it
is
a pain in the butt.

Pure copper is gummy and tricky to turn. You can do it, but it requires
careful tuning of tools, speeds, and feeds to get consistent results.

There are some "free machining" copper alloys that are made for machining,
such as tellurium copper (C14500). It's used to make welding and cutting
torch tips, etc., and for EDM electrodes, because it cuts cleanly, or
reasonably so.

To many materials engineers, all copper alloys are "bronze." That even
includes yellow brass. You'll see in the literature that bronze has been
used for bullets, but I've never noticed which alloys are used.

--
Ed Huntress