The gate plate of ordinary butterfly valves is made of carbon steel, ductile iron or stainless steel.

Carbon steel, also called carbon steel, refers to an iron-carbon alloy with a carbon content Wc less than 2.11. In addition to carbon, carbon steel generally contains small amounts of silicon, manganese, sulfur, and phosphorus. Ductile iron is a high-strength cast iron material developed in the 1950s. Its comprehensive performance is close to that of steel. Based on its excellent performance, it has been successfully used to cast some complex stress-bearing materials with strength, toughness, and wear resistance. Parts with higher performance requirements. Ductile iron has rapidly developed into a widely used cast iron material second only to gray cast iron. The so-called "replacing steel with iron" mainly refers to ductile iron.