Agile-shop Rotary Burr Set HSS Rotary Files For Metal Plastic Wood Grinding 6pcs 6mm 1/4" Soft Metal Application: suitable for grinding metal, plastic, wood, soft metal etc Application of machine tool: Electric grinder Suitable for: all kinds of wood; soft metal like aluminum, cuprum; most plastic Rotary Cutter files Set Type: Rotary Burr Cutter Rotary Burr Shank Diameter: 1/4''(6mm)