Before we had centerless grinding, round parts we needed to manufacture were either ground between centers or by gripping them with a chuck or fixture. Centerless grinding requires nothing like that, instead parts are fed between a grinding wheel and a smaller regulating wheel while resting on an angled workpiece support, which is a blade-like device that sits between the opposing wheels. This kind of grinding is critical for manufacturing high-volume automotive components including valve spools, control rods, camshafts, crankshafts, pistons, sleeves, and rollers. Not only is this kind of grinding important for the automotive industry, but also for the medical and aerospace industries, basically any industry where you need an extremely accurate round object to complete the project you're doing. There are three forms of centerless grinding and they are through-feed centerless grinding, end-feed centerless grinding, and in-feed centerless grinding. - In through-feed grindi