Re: [ATM] microwave glass kiln: lead free graphite

["Bob May" <rmay@nethere.com>]

Never saw graphite used for plastic injection molds.  It is way
too soft for evcen a short run.  Maybe as a vacuum type mold for
epoxies and other two part  plastics but not for the thousands of
pounds of pressure that a plastic injection machine can generate.
I've used aluminum for molding and that works well if you get the
riht kind of aluminum as some of it is cast of relatively pure
al. and that stuff just does not care to mill well.  I'm talking
about cutters that are doing a six thousandths of an inch ball or
rounded bottom cut.  You just don't want to have that cutter get
loaded up with aluminu m and twist the end off!  Breass is a lot
better material for cutting molds with but it is a lot more
expensive.  Steel, while cheap, is a fair bit harder than the
others and thus is more difficult to cut in a rapid fashion.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


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