This video shot by Boeing St. Louis illustrates plunge roughing in aluminum with a 2-inch-diameter tool at 0.3 radial depth of cut, to a depth of 8.75 inch depth of cut. Feed rate is 300 ipm and metal removal rate is 72 cubic inches per minute. Because of the high metal removal rate, Boeing often recommends the use of plunge roughing as part of a strategy for making efficient use of lower-rpm machining centers—even when the workpiece material is aluminum. For more, see the article under “Editor Picks” at right.