Believe it or not, but this is actually in slow motion! Originally valve jobs were "ground" via stones that were cut in various angles. The majority of the machining industry now uses machines to cut valve jobs, but most are multi angle cutters. So rather than cutting each angle one at a time, you can cut 3-5 (sometimes more) all in one hit! The benefits are speed and consistency with angle widths. These cutters have pre-determined angles that are really basic to fully custom. The downside? When