On Mon, 12 Dec 2005 22:48:37 -0500, "Bob Chilcoat"
wrote:

I may actually never have tried to machine actual cast iron before (except
for drilling and tapping a few holes). I have machined plenty of mild
steel, however. I guess that's a different animal. I'm not sure what this
is, but I'm willing to concede that it's probably cast iron. The Browning
taper-lock hub, OTOH, is almost certainly a powdered metal part. It is
clearly molded with mold parting lines and fine detail. Not sand cast or
what I've ever seen from cast iron. That's what led me to believe the
sheave was PM too. Live and learn.

Sintered or pressed metals often behave far differntly, even when of
the same material..due to compression when molding and heat treating
effects.

I turned something once that I KNOW was cast iron..and got chips. My
customers turn powderd metal every day..and get fines.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner