It is Engraving Bits/3-Edge Drill Bits/CNC Cutter/End Mill/CNC Router Bits. Product Type: pyramid engraving bit with 3 cutting edges. Shape: trigonous shape. Material: solid carbide. Application: It is designed mainly for the rotary engraving and marking of Copper, Aluminum, Jade, Redwood, Hardwood, Acrylic, Color Plates, PVC, MDF and PCB etc.