What's the difference between 42CrMo steel and 42CrMo4 steel

42CrMo steel is a medium carbon alloy structural steel with good comprehensive properties and hardenability. It is commonly used in the manufacturing of gear, connecting rod, high-strength bolt and other important parts in the processing. Is the European standard 42CrMo4 steel a substitute for 42CrMo steel? What is the difference between 42CrMo steel and 42CrMo4 steel?

42CrMo steel and 42CrMo4 steel come from different standards of different countries. 42CrMo steel is the specification of material and alloy structural steel in Chinese standard GB3077. 42CrMo4 steel belongs to EN10083 quenched and tempered steel.

There are chemical differences between 42CrMo steel and 42CrMo4 steel. For example, the content of Si in 42CrMo steel is smaller than that in EN10083. In addition, according to GB3077, P and S content can be divided into three grades, while EN10083 only limits its maximum content.

42CrMo steel and 42CrMo4 steel have different hardenability requirements. The hardenability of GB3077 has no specific value of quenching bandwidth. If there are special requirements, the buyer and the supplier can discuss the solution on their own. The specific value of hardening bandwidth is specified in EN10083. EN10083 has three grades H, HL and HH for reference when ordering.