42CrMo is an alloy steel material, the main components include carbon, silicon, manganese, phosphorus, sulfur, chromium, molybdenum and other elements, of which chromium and molybdenum are the main alloying elements of the material. 42CrMo steel is an ultra-high strength steel, which has high strength and toughness, good hardenability, no obvious tempering brittleness, high fatigue limit and multiple impact resistance after quenching and tempering treatment, and good low-temperature impact toughness.

No. 45 round steel is a high-quality carbon structural steel plate, corresponding to Japanese standard S45C, American standard: 1045, German standard C45. It is characterized by its higher strength and resistance to deformation than ordinary A3 steel.

40Cr is the standard steel grade of China's GB, and 40Cr steel is one of the most widely used steels in the machinery manufacturing industry. After quenching and tempering treatment, it has good comprehensive mechanical properties, good low-temperature impact toughness and low notch sensitivity.

16Mn is one of the materials in steel. A name for the material of steel pipe. It has good comprehensive performance, good low temperature performance, good stamping performance, welding performance and machinability. However, since the hardening tendency of 16Mn steel is slightly larger than that of mild steel, preheating measures are required to prevent cold cracks when welding at low temperatures (such as winter open-air operations) or on large rigidity and large thickness structures.