Trapezoidal buckle Flange nut wall thread Flange nut hexagon nut water stop screw nut

Fastener is the general name of a kind of Machine element used to fasten two or more parts (or components) into a whole. Among them, self fastening fasteners are widely used in the connection of sheet metal parts due to their advantages of fast installation, high efficiency, reliability, convenient assembly, high push, pull, and torque performance, wide range of applicable materials, and standardized serialization. Nuts are the most widely used type of fastener. With the continuous changes and development of the scope and environment of use, there is also a greater demand for nuts. Especially in some situations, nuts are required to have waterproof and sealing functions. There are generally several types of sealing and waterproofing methods for existing nuts:

Stainless steel Rivet nut are used on railway passenger cars, highway passenger cars and ships. Their main function is to connect non structural load-bearing bolts. The main advantage of stainless steel Rivet nut is that there is no operating space on the back of the base material and it can still be used, and its weight is extremely light. Today, I will talk about the principles of material selection of stainless steel Rivet nut and their uses: 1. Requirements on mechanical properties, especially strength of stainless steel rivet nuts; 2. Requirements for corrosion resistance of materials under operating conditions;

"Screw refers to a screw (foreign name: Screw), which is a tool that uses the physical and mathematical principles of the oblique circular rotation and friction of an object to gradually tighten the mechanical components of the object. Screws are a common term for fasteners, commonly used in everyday language.
Metric threads are measured in millimeters (MM) and have a tooth tip angle of 60 degrees. Both American and British threads are measured in inches. The cusp angle of American threads is also 60 degrees, while the cusp angle of British threads is 55 degrees"

"At present, there are three main materials of standard parts in the market: carbon steel, stainless steel, and copper.
One carbon steel. We distinguish low carbon steel, medium carbon steel, high carbon steel, and alloy steel based on the carbon content in carbon steel materials.
Low carbon steel with C% ≤ 0.25% is commonly referred to as A3 steel in China. Basically referred to as 1008101510181022 in foreign countries. Mainly used for products without hardness requirements such as grade 4.8 bolts, grade 4 nuts, and small screws. (Note: The drilling tail nail is mainly made of 1022 material.)
2% carbon steel 0.25%
3. High carbon steel C%>0.45%. Basically not used in the market
4 alloy steel: Adding alloy elements to plain carbon steel increases some special properties of the steel, such as 35, 40 chromium molybdenum, SCM435, and 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, with main components including C, Si, Mn, P, S, Cr, and Mo.
Two stainless steels. Performance level: 45, 50, 60, 70, 80
1. The main components of austenite (18% Cr, 8% Ni) have good heat resistance, corrosion resistance, and weldability. A1, A2, A4
2 Martensite and 13% Cr have poor corrosion resistance, high strength and good wear resistance. C1, C2, C4 ferritic stainless steel. 18% Cr has better upsetting performance and corrosion resistance than Martensite. The main imported materials in the market are from Japan. Mainly divided into SUS302, SUS304, and SUS316 by level.
Three copper. The commonly used material is brass... zinc copper alloy. H62, H65, and H68 copper are mainly used as standard parts in the market"

The national standard requirement for the screw size in the pan head combination screw and round head triple combination screw is GB818. The main technical requirements for various types are: material requirements include iron and stainless steel, iron includes low, medium, and high carbon steel, and stainless steel combination screw materials include stainless steel 201, stainless steel 304, and stainless steel 316. The thread tolerance is 6G, and the mechanical performance levels of iron composite screws are 4.8 and 8.8. 4.8 composite screws are ordinary steel, with a maximum allowable hardness of 255HV. 8.8 composite screws are generally made of 10B21 wire, and then subjected to hardening treatment before hydrogen removal. The purpose of hydrogen removal is to prevent hydrogen embrittlement of the spring washer in the combination screw. Prevent the spring pad from breaking. The tolerance level of the combination screw is A. The cross groove should be H-shaped. The surface treatment of combination screws can be environmentally friendly or non environmentally friendly. Specially, environmentally friendly blue zinc, environmentally friendly color zinc, black zinc, color zinc, white nickel, and so on. The technical requirement for the combination screw to the elastic flat washer is that the washer should be able to automatically rotate without falling off.