ITEM NAME:8mm Shank CNC Router Bottom Cleaning Bit Milling Description: 3 Sizes 8mm Router CNC Engraving Woodworking V Groove Bottom Cleaning Bit 8*15MM+8*17MM+8*18MM Using for hand-making or woodworking Industrial Quality Router Bits The is made of high quality tungsten steel alloy forging , body is made of titanium steel material(HSS) Build-up & Heat Resistant Coating Baked on heat resistant coating prevents build-up of sawdust, resin, and pitch. Industrial grade micro grain car.Shank Diamter: 8mm( 5/16"). Baked on heat resistant coating prevents build-up of sawdust, resin, and pitch. Build-up & Heat Resistant Coating. The is made of high quality tungsten steel alloy forging, body is made of titanium steel material(HSS).