Round head screw, hexagonal small screw, non-standard multi tapping step screw, high-precision special screw

Spring washers are designed for screw locking, usually single coil cylindrical spiral springs. To improve their locking function, integrated spring washers are also used. Their structure is that the inner ring of the flat washer has multiple wings, each wing folded into a spring plate. Another type of washer similar to spring washers used for backstop is a serrated lock washer. However, this type of lock washer usually has a smaller thickness and forms serrations on the inner or outer ring of the washer on a flat surface through bending. When tightening, it has less elasticity and is easy to be flattened, making the locking function still not strong enough.

Double headed bolts generally require surface treatment, and there are many types of surface treatment for bolts, including electroplating, blackening, oxidation, phosphating, and non electrolytic zinc sheet coating treatment. However, electroplating fasteners account for a large proportion in the actual use of fasteners. Especially widely used in industries and fields such as automobiles, tractors, household appliances, instrumentation, aerospace, communication, etc. However, for Threaded fastener, it is not only required to have certain anti-corrosion capacity in use, but also to ensure the interchangeability of threads, which can also be called screwing in here. In order to meet the dual use performance of "anti-corrosion" and "interchangeability" required in the use of Threaded fastener at the same time, it is very necessary to develop special plating standards. GB/T5267.1-2002 [Electroplated Coatings on Threaded fastener] is one of the national standards "Fastener Surface Treatment" series, which includes: GB/T5267.1-2002 [Electroplated Coatings on Fasteners]; GB/T5267.2-2002 [Non electrolytic zinc sheet coating for fasteners] two standards. This standard is equivalent to the international standard ISO4042; 1999 [Electroplated coating of Threaded fastener]. This standard replaces GB/T5267-1985 [Electroplated coating of Threaded fastener].

"3. Friction coefficient
The friction angle is an important factor affecting the tightening torque, and the existence of friction is the basis for the normal operation of the locking nut. When the locking nut is working, there is pressure and friction on the contact surface under the elastic restoring force of the threaded piece. During repeated use, the rough positions and edges of the contact surface are smoothed by the cyclic friction, resulting in a smaller friction coefficient and a decrease in the maximum tightening torque of the nut"

A nut is a nut, a component that is screwed together with a bolt or screw to tighten. All production and manufacturing machinery must use a component that is divided into several types based on different materials, such as carbon steel, stainless steel, and non-ferrous metals (such as copper). Chinese name Nut, foreign name crewnut, alias Nut properties and tightening effect when screwed together with bolts or screws. Types of carbon steel, stainless steel, non-ferrous metal standards, national standards, German standards, international standards, Japanese standards, American standards, features, easy installation, integrity, no washer disassembly, convenient materials, carbon steel, stainless steel, copper, alloys, etc