The X-LOCK Type-27 general-purpose abrasive grinding wheels are ideal for general grinding of ferrous metals, including alloy steel, carbon steel, stainless steel, cast iron and wrought iron. These wheels are constructed of high-purity white aluminum oxide abrasive grains for increased performance and added durability. The X-LOCK quick change system provides up to 5X faster wheel changes vs. a standard angle grinder mount. Simply pull the release lever on the X-LOCK angle grinder and change the wire cup brush - no tools needed.