with an ideal combination of free and combined carbon to provide prolonged working life. The casting used has a very fine grain to provide high tension even at elevated temperatures of high-speed engines. Hard chromium is Electro-deposited on the periphery of piston rings to achieve high abrasive wear. Duaflex oil control piston rings are chromium plated on their fully radiused edges to provide wear resistance wiping surface free of sharp corners or cutting edges which may cause bore wear. Each iron ring is Parco lubrized and it produces a lightly etched surface to provide oil retaining phosphate coating. This type of surface minimises scuffing, assists running in and affords some protection during stotage. Each of piston rings is properly inspected by modern techniques to ensure material and dimensional accuracy for the best results of high compression and less oil usage.