8Pcs Carbide Rotary Drill Files 1/4" Shank Double Cut Rotary Velcro Bit Set Engraving Tool for Electric or Air Tools Features:Carbide rotary files are widely used and are used in mold processing and manufacturing. Chamfering, rounding and grooving of machine parts. The processing quality is good, the finish is high, and the service life is long. Various precision mold cavities can be processed. Machining of cast iron, cast steel, carbon steel, alloy steel, stainless steel, copper, aluminum, etc. Metals as well as non-metals such as marble, jade and bone. Easy to master, easy to use, safe and reliable. Heavy manual labor is greatly reduced and production costs are reduced. Widely used in machinery, automobiles, shipbuilding, chemical industry, craft sculptures, etc. Carbide rotary files are mainly used with power tools or power tools or pneumatic tools. (Can also be installed on the machine)Specifications:Material: CarbideShank Diameter: 1/4" (6.35mm)Grooves: Double RotationHardness: Can Up to HRC70Quantity: 8/SetPackage Included:8pcs Tungsten Carbide Rotary Drill Bits