The flat pad is mainly punched out with iron plate. The shape is generally a flat washer with a hole in the middle. This hole size specification is generally based on customer requirements.

Flat washers are usually thin pieces of various shapes used to reduce friction, prevent leakage, isolate, prevent loosening or disperse pressure. This material is found in many materials and structures to perform a variety of similar functions. Due to the material and process limitations of the threaded fasteners, the support surface of the fasteners such as bolts is not large. Therefore, in order to reduce the compressive stress of the pressure receiving surface, the surface of the connected member is protected, and a gasket is used. In order to prevent the looseness of the connecting pair, a loose spring washer and a multi-tooth lock washer, a round nut retaining washer, and a saddle-shaped, wave-shaped, tapered elastic washer are used.

There are 9 standard flat washers in China. From 2000 to 2002, GB/T97.3-2000, GB/T5286-2001, GB/T95-2002, GB/T96.1-2002, GB/T96.2 were approved. -2002, GB/T97.1-2002, GB/T97.2-2002, GB/T97.4-2002 and GB/T5287-2002 and other flat washer standards.

According to the flat washer performance level, I recommend the use of materials:

For the optional 10012 HV grade ST12, ST13 and Q235, Q215, Q195, etc., the surface hardness can reach about 110HV;

For the optional 140HV class 08F, 08Al and 10, 10F, etc., the surface hardness can reach about 140HV;

For the 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 achieve the technical requirements of 200-300 HV and 300-400 HV.