GB/T 5283-1985

This standard specifies the dimensional, mechanical, and material requirements for slotted countersunk head tapping screws designed to form their own mating threads when driven into pre-drilled holes in materials such as sheet metal, plastics, or wood. It is applied in mechanical assembly and manufacturing contexts where a flush or countersunk screw head is needed for a smooth surface finish, commonly in automotive, electronics, and general hardware products. The standard ensures interchangeability and consistent performance for these fasteners in industrial production and quality testing.