Grinding wheels smooth and finish metal and sharpen tools. They install on handheld tools for offhand grinding or when workpieces are large and high precision is not needed. Grinding wheels installed in stationary or bench grinders are used when the workpiece is small enough to hold or when high precision or high-polish finishes are needed. Depressed-center grinding wheels install in angle grinders to smooth weld lines, bevel edges, and remove stock. Diamond segment cup grinding wheels smooth granite, stone, concrete, and masonry. Bench and pedestal grinding wheels shape and debur metal and sharpen tools. Surface and cylindrical grinding wheels smooth and leave a fine finish on surfaces. Tool and cutter grinding wheels sharpen and hone cutting tools, such as end mills and reamers. Foundry grinding wheels are generally vey coarse and are used for snagging and other foundry work on cast iron.