Fangrui Product Details [detail]: There Are Complete And Evenly Distributed Particles On The Chainsaw Bits, It Can Sharpen The Chain Saw Chain Steadily And Efficiently. [premium Quality]: Burr Grinding Stone File Is Made Of High Quality Material With Good Hardness, Adopted Titanium Plating Process, Durable And Not Easy To Get Broken, You Will Enjoy Longer Lifetime Of These Bits Than Others Non-titanium-plated. [easy To Operate]: These Bits Are Specially Designed For Electric Chainsaw Sharpener. You Can Apply It To Polish Without Disassembling The Chain, Which Reduces The Number Of Times You Have To It. Effectively Improving Work Efficiency. [application Occasions]:3/16 Inch Wheels For 325 Inch Chain, Big 3/8 Chainsaw Chain. These Polishing Grinding Tools Are Widely Applied For Machinery, Bearing, Mold, Casting Parts Deep Hole, Different Internal Surface, Welding Spot, Welding Seam Grinding And Burr Grinding. [tips]: If There Are Black Spots On The Surface Of The Wheel. Thats Just A Mixture Of Titanium And Silicon Ca