The bolt is a mechanical part, with a cylindrical nut with threaded fasteners. By the head and screw two parts of a class of fasteners, need to cooperate with the nut, used to fasten the connection of two parts with a through hole. This form of connection is called bolt connection. Such as the nut from the bolt screw down, and can make the two parts separate, so the bolt connection is a removable connection.
Classification of bolts
According to the connection of the force can be categorized into ordinary and reamed holes. According to the shape of the head, there are hexagonal heads, round heads, square heads, countersunk heads and so on. Among them, the hexagonal head is the most commonly used. Generally, the countersunk head is used where connection is required.
According to the thread type can be divided into coarse and fine teeth. Bolts are divided into eight grades according to their performance level: 3.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9. Among them, 8.8 grade or above (including 8.8 grade) bolts made of low-carbon alloy steel or medium-carbon steel and heat-treated, commonly known as high-strength bolts, 8.8 grade or below (excluding 8.8 grade) usually known as ordinary bolts.
Application of bolts
Bolts are tools that use the physics and mathematics of the circular rotation of an object's inclined plane and friction to tighten artifact mechanisms gradually.
Bolts are indispensable in daily life and industrial production, which shows the wide application of bolts. The scope of application of bolts is electronic products, mechanical products, digital products, power equipment, and electromechanical products. Ships, vehicles, water conservancy projects, and even chemical experiments are also used in the bolt. Anyway, it is a lot of places are used for bolts. In particular, such as digital products above the use of precision bolts, DVDs, cameras, glasses, clocks and watches, electronics and other micro-bolts; TV, electrical products, musical instruments, furniture and other general bolts; as for engineering, construction, bridges, the use of large bolts, nuts; transportation equipment, airplanes, trolleybuses, automobiles and so on for the size of the bolts and use. Bolts are very important in industry, as long as there is industry on earth, the bolt is always important.