Grinding valve seats with abrasive stones has been aound about as long as the internal combustion engine. In the early days of grinding seats, there were only two abrasive materials to choose from – General Purpose and Finishing – because seats were mostly made of a single material, cast iron. Today, seats are made of
Today, seats are made of a wide variety of materials, different combinations of various alloys, powdered metals and other super hard materials. This seat material is designed to prolong the ability of the valve seat to seal against the pounding of the valve head during engine operation. The variety of materials also means new and different abrasives are required for proper machining.