A Triangular CNC Blade (triangular insert) is a hard metal cutting tip , typically made of tungsten carbide, cermet, ceramic, or coated carbide , designed to be mounted on a tool holder .Each corner of the triangle can serve as a cutting edge , so when one edge wears out, the insert can be rotated to use another corner — extending tool life. Structure & Features Feature Description Shape Equilateral triangle with 3 usable corners (each 60° cutting edge). Material Usually