ITEM NAME:100mm 4" Carbon Steel Diamond Coated Grinding Disc Rotary Cutting Cut Off WheME Features 100% brand new. Great tool for DIY, craft work, jewelry making or silver smithing. With both sides coated around borders. Ideal For Cutting: Gem stones, metal, glass, ceramics, porcelain, tiles, car.Material: Carbon steel. Cutting Disc 1. With both sides coated around borders. 100 mm/3.94". Great tool for DIY, craft work, jewelry making or silver smithing.