A flat washer is also called a flat washer. It is mainly stamped out of an iron plate. The shape is generally a flat washer with a hole in the middle. The size of this hole is generally determined according to customer requirements. There are 9 standards for flat washers in my country. From 2000-2002, GB/T97.3-2000, GB/T5286-2001, GB/T95-2002, GB/T96.1-2002, GB/T96.2 were approved and released respectively. -2002, GB/T97.1-2002, GB/T97.2-2002, GB/T97.4-2002 and GB/T5287-2002 Standard for Flat Washers. According to the performance level of the flat washer, the following materials are recommended by MSC: ST12, ST13, Q235, Q215, Q195, etc. can be selected for the 100HV level, and the surface hardness can reach about 110HV; for the 140HV level, the Select 08F, 08Al and 10, 10F, etc., the surface hardness can reach about 140HV; for 200HV and 300HV grades, 45, 50, 60, 70 steel or 65Mn steel should be selected, which can be quenched and tempered by heat treatment to reach 200 ~ 300HV and 300 ~400HV technical requirements.