The Dewalt DT40251 Extreme Diamond Edge is made from solid steel that greatly reduces the risk of breakage The Dewalt DT40251 EXTREME METAL cut-off discs feature diamond technology for extreme durability and maximum work efficiency. They deliver 1,000+ cuts which is 30 times longer than thin bonded cut-off wheels. Manufactured for corded and cordless Angle Grinders. Features: 1000+ cuts : Extreme Diamond Edge is made with metal cutting diamonds bonded to the wheel's surface using a proprietary technology Increased safety : Extreme Diamond Edge is made from solid steel that greatly reduces the risk of breakage No shelf life : Unlike bonded abrasives, Extreme Diamond Edge will not expire, as long as it is stored in proper conditions Diameter retention : Because its' diamond cutting edge doesn't wear away, Extreme Diamond Edge holds its' original wheel diameter until the very last cut Less dust, better workspace : Because Extreme Diamond Edge doesn't wear out there is substantial reduction of airborne particles One wheel - multiple metals : Extreme Diamond Edge works in a wide range of materials including steel, stainless steel, cast iron, rebar, sheet metal, aluminium and non-ferrous metals Specification: Diameter: 115mm Bore Size: 22.23mm Thickness of Diamond Segment: 1.3mm