Fangrui Product Details Carbide Rotary Burrs Durable Routing Router Drill Bits Premium Quality Rotary Cutter File Versatile Root Carving Milling Cutter Description: Brand-new And High Quality Made Of Hhs High Speed Steel, Durable,wearproof. Portable, Easy To Carry And Install. One Set Has 6pcs , Different Use For Your Demand. For Processing Of Metallic And Non-metallic Surfaces All Of The Shanks Are 3.17mm, Can Be Used For Engraving, Polishing,etc. Diameter Parameters: Material: Hhs Color: Silver Quantity:6pcs Size: Triangle :head 3.17mm Shank 3.17mm Cylindrical :head 3.17mm Shank 3.17mm Inverted Cone :head 3.1mm Shank 3.17mm Ball : Head 3.1mm Shank 3.17mm Umbrella : Head 6mm Shank 3.17mm Large-toothed: Head 8mm Shank 3.17mm Specifications: Package Included: 6x Hss Rotary Files Notes: Carbide Burrs Speed Is Generally 6000-40000 Rev / Min When Used On Pneumatic Or Electric Tools, The Tool Must Be Clamped Tight. Cutting Direction Should Move From Right To Left Smoothly, Do Not Cut Back And Forth As Using The Wheel; Be Careful Not To Use Too Much Force (pressure Is Generally Not More Than 4 Kg). Due To The Difference Between Different Monitors, The Pictures May Not Reflect The Actual Color Of The Item. Compare The Detail Sizes With Yours, Please Allow Little Error, Due To Manual Measu