Structural parameters and functional uses of bolts.

Structural parameter

According to the force mode of the connection, it is divided into ordinary and hinged holes. According to the shape of the head: hexagonal head, round head, square head, countersunk head and so on. The hexagonal head is the most commonly used. Generally, the countersunk head is used where the connection is required.

The English name of the riding bolt is U-bolt, non-standard parts, the shape is U-shaped so it is also known as U-bolt, and the thread at both ends can be combined with the nut, mainly used to fix the pipe such as water pipe or flake such as the plate spring of the car, because the way of fixing the object is like a person riding on a horse, it is called the riding bolt. According to the length of the thread is divided into full thread and non-full thread two categories.

It is divided into coarse teeth and fine teeth according to the tooth type of the thread, and the coarse teeth type is not shown in the mark of the bolt. Bolts are divided into 3.6, 4.8, 5.6, 5.8, 8.8, 9.8, 10.9, 12.9 eight grades according to the performance level, of which 8.8 (including 8.8) bolts are made of low carbon alloy steel or medium carbon steel and heat treatment (quenching + tempering), generally known as high strength bolts, 8.8 (excluding 8.8) are commonly known as ordinary bolts.

Ordinary bolts according to the production accuracy can be divided into A, B, C three grades, A, B for refined bolts, C for coarse bolts. For the connection bolts for steel structures, unless otherwise specified, they are generally ordinary crude C-class bolts. There are differences in the processing methods of different levels, usually corresponding to the processing methods as follows: ① the bolt rod of A and B bolts is processed by lathe, the surface is smooth, the size is accurate, the material performance grade is 8.8, the production and installation is complex, the price is high, and it is rarely used; Class C bolts are made of unprocessed round steel, the size is not accurate enough, and the material performance grade is 4.6 or 4.8. The shear connection deformation is large, but the installation is convenient, the production cost is low, and it is mostly used for temporary fixing during tensile connection or installation.

Functional use

There are many names for bolts, and everyone's name may be different, some people are called screws, some people are called bolts, and some people are called fasteners. Although there are so many names, but the meaning is the same, are bolts. Bolt is a general term for fasteners. The bolt is a tool to tighten the parts step by step using the physical and mathematical principles of the inclined plane circular rotation and friction force of the object.

Bolts are indispensable in daily life and industrial production and manufacturing, and bolts are also known as industrial meters. It can be seen that the use of bolts is wide. The application range of bolts is: electronic products, mechanical products, digital products, power equipment, mechanical and electrical machinery products. Bolts are also used in ships, vehicles, hydraulic projects, and even chemical experiments. Bolts are used in a lot of places anyway. Such as the precision bolts used in digital products. Miniature bolts for DVDS, cameras, glasses, clocks, electronics, etc. General bolts for televisions, electrical products, Musical Instruments, furniture, etc.; For projects, buildings and Bridges, large bolts and nuts are used; Transportation equipment, aircraft, trams, cars, etc., are used with large and small bolts. Bolts have important tasks in industry, and as long as there is industry on Earth, the function of bolts will always be important.