The fastener is divided into bolt, stud, screw, self tapping screws, washers, retaining ring, pin, rivet, assembly and connection, welding nail etc., are widely used in machinery and equipment, vehicles and ships, airplanes and satellites, railway bridges, buildings, equipment, instrumentation and other fields.

Factors affect the quality of fastener products including the management level of a company, talent and technology skills, quality inspection capability of product and market conditions and other factors. Especially in quality control products, due to the standard understanding is not correct, method of operation is not standard, equipment does not meet the requirements, environmental control shall be and other reasons, resulting in the detection data is not accurate, even entirely wrong, cause the enterprise on the quality of batch products decision deviate, process adjustment direction error, become the product poor quality stability, the product quality claims, trade disputes.

The mechanical properties of training including GB/T 228, GB/T 3098.1, GB/T 3098.6, GB/T 3098.13, GB/T 1231, the standard test method for GB/T 3632 and ASTM, SAE etc..