Material: Tungsten Carbide Rotary Cutter Set, Processing Hardness Can Reach Up To Hra70, Sturdy And Durable. Shank Diameter: 1/8 Inch (3Mm), Grinding Heads Diameter: 1/4 Inch (6Mm), Please Check The Size Before Purchasing.Double Cut Design: The Cutter Set Double-Cut Carbide Rotary Bits Combining Left And Right Flutes To Produce A Chisel-Like Edge Reduces The Pulling Action, Allowing Greater Operator Control. More Cutting Edges Will Remove Material Faster And Leave A Smoother Finish Than A Single Cut.Versatile: Rotating Tip Cutters In 10 Different Shapes Meet Your Needs For Carving, Finishing, Cleaning , Smoothing, Grinding Grooves, Polishing And Removing Sharp Edges And Even Processing A Variety Of High-Precision Mold Cavities.Used In A Variety Of Materials: The Grinder Drill Bit Is Suitable For Processing A Variety Of Metals, Such As Copper, Aluminum, Alloys, Iron, Hardened Steel And Non-Metallic Metals Such As Marble, Jade, Bone, Wood, Fiberglass Glass, Plastic, Etc. .Perfect Suitable For All Materials.Compatibility: With Widely Adopted 1/8" Shank, Suitable For Most Rotary Tools With 1/8" Collet Such As Pneumatic Rotary Tools And High-Speed Engravers. Speed, Also In Machine Tools Or Grinders. Easy To Change And Meets Most Of Your Drilling Needs.