Hi: I am machining some pump vanes (oilfield parts) out of A.B. These things have to have almost sharp corners when i'm done. Right now i'm using a file and a lapping plate. I can't seem to finish cut these things without some over hang (burrs) which are very hard to remove. I am doing this on a manual milling machine. Does anyone have an idea of a feed and speed i could use to eliminate this?