Thanx for replying-I thought this thread had died. Years ago in machining class we used kerosene on alum. and it also worked great. I'm switched to a fairly heavy oil with sulphur in it that our punch press dept. uses and it doing ok. I'm using a 3/16" cobalt endmill to cut small windows in this casting. I couldn't figure out why I had to run such slow rpms but found out these castings have been hardened through a heat -treating operation so that might explain it. It's wearing out my tools pretty quickly. The speeds and feeds you mentioned sound like what I run on 2024 and 6061 alum. but couldn't possibly do that on these parts plus I have a pretty flaky set-up. I'm on a sine-bar clamped to a 3/4"piece of steel sticking about 8" above the vise and clamped to it with 3 clamps so I don't want too much in the way of tool pressure. Thanx again. |