OK...I'll ask a dumb question...Isn't drill rod already pretty hard? How
much harder could you make it? Anyone know the Rc hardness of drill rod ?
Thanks

"Dave Lyon" wrote in message
news:w91hf.352861$084.317296@attbi_s22...

This may sound like a dumb question to those in the know, but why can't
you
turn the parts about .0006 under, and then heat treat? Would it be a
surface finish problem, or distortion or something I haven't thought of?
Just curious.



The main problem is that the growth will be nearly impossible to predict.
In
some metals (like H-13) some areas may actually shrink. The growth usually
is proportional to the size of the part, where small parts grow very
little,
and larger parts grow more. In most materials, you can count on around
.0007" growth per inch. Usually, depending on the quality of the heat
treatment process, you can expect different amounts of growth in different
areas. Plan on the part coming back out of round. If you're trying to hold
a
.0003" tolerance, you better count on machining after heat treat.