Piston ring: commonly used materials are cast iron and steel. Cast iron can be divided into nodular cast iron and malleable cast iron. Among the steel, 65Mn spring steel can be used to make gas ring; Surface treatment methods include chromium plating, tin plating, molybdenum spraying and phosphating; The processing methods include monomer casting, profiling and heat fixation. For motorcycles, alloy cast iron (Cr Mo, W alloy cast iron), nodular cast iron and steel (spring steel, stainless steel) can be used.

    Crankshaft: it can be divided into forged crankshaft and cast crankshaft. The common materials of forged crankshaft are ordinary carbon steel (35, 40, 45, 50) and alloy steel (35Mn2, 40Cr, 45Mn2, 35CrMoA, 42CrMoA, etc.), and the common materials of cast crankshaft are nodular cast iron, malleable cast iron, alloy cast iron and cast steel, etc; Forged and cast crankshafts are generally subject to heat treatment, and the journal part is subject to hardening treatment (carburizing, nitriding, quenching) and grinding. Crankshaft bearing materials can be divided into lead base, tin base, copper base and aluminum base bearing alloys. For motorcycles, most of them are combined crankshafts (multi cylinder ones are integral ones), which are mostly forged. The common surface strengthening processes include high frequency induction hardening, fillet rolling and nitriding.