March 2012 / Volume 64 / No. 3

Take the Plunge
In plunge milling, the rotating cutting tool moves straight into the workpiece in the Z-axis, retreats in the same direction and then steps over in the X- or Y-axis to make an overlapping vertical cut and remove more material. Plunge milling provides a range of benefits. Especially in long-reach applications, such as deep mold features, traditional side-to-side, or planar, milling is slowed by the need to minimize the lateral forces that cause chatter. When plunge milling, cutting forces are directed into the spindle and the machine table, and metal-removal rates can be much higher than in traditional milling.