6pcs 6mm 1/4" Rotary Burr Set Electric Grinder Hss Rotary Files Burr for Soft Metal, Plastic, Wood Grinding, Carving Cutter Rotary Burr Shank Diameter: 1/4''(6mm) Suitable for: all kinds of wood; soft metal like aluminum, cuprum; most plastic Rotary Cutter files Set Type: Rotary Burr Material: High Speed Steel Application of Machine Tool: Electric Grinder