3.175MM Shank Diameter Carbide End Milling Cutter, Engraving Edge Cutter, CNC Router End Mill for PCB Machine Pack of 10 Shank diameter: 3.175mm /0.125 inch Cutting edge diameter: 3.175mm These Engraving bits have sufficient flexural strength and wear resistance Milling, hole and plate edge, surface clean, tidy, no burr