Going to machine some 3/4" alloy 630 extruded nickel-aluminum bronze alloy.
It shows a machinability rating of 30, with FC brass being 100%. I would
guess with this machinability rating, there are some problems drilling and
machining this material. This alloy 630 is comparable to Ampco-45. What
should I be looking for, as far a cutting speeds, lubricant, and cutting
bits (HSS or other)? Plan to make a couple oversized valve guides, if I can
get the hang of machining this material.
Larry

"Larry & Cindy" wrote in message
...
Going to machine some 3/4" alloy 630 extruded nickel-aluminum bronze
alloy.
It shows a machinability rating of 30, with FC brass being 100%. I would
guess with this machinability rating, there are some problems drilling and
machining this material. This alloy 630 is comparable to Ampco-45. What
should I be looking for, as far a cutting speeds, lubricant, and cutting
bits (HSS or other)? Plan to make a couple oversized valve guides, if I
can
get the hang of machining this material.
Larry


Slow speeds, light feeds and sharp tools. Don't let your tools get dull,
and watch that your drill doesn't seize in the hole. Some of the copper
alloys are truly a bitch to drill. You may find carbide (C2 grade) will
hold up quite well as opposed to HSS---but you'll need to be able to sharpen
the tool unless you have inserts. I'd suggest only positive rake for this
stuff. It is likely to have characteristics much like the 300 series
stainless (except for 303 S or Se), tough, but not hard, so handle it much
the same way. Sulfur based oil will seriously discolor it, so use lard oil
if you have it. Should cut clean. I'm betting it won't drill well..
I'd be interested in hearing how it goes.

Harold