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What are the classification and use of high strength bolts?
Date：May 3rd,2023
High strength bolt is a special bolt made of high quality carbon steel or low alloy steel material. It is called a high strength bolt because of its high strength. High strength bolt connection has the advantages of simple and quick installation, good stress performance, installation and disassembly, high pressure, safety and reliability.
High-strength bolt is a new type of steel structure connection mode developed after riveting connection, which has been developed into one of the main means of steel structure connection today.
1. Classification of the high-strength bolts
High strength bolts can be divided into two types: hexagonal head and torsion shear; 8.8,10.9,12.9 by performance grade. Currently, the high strength bolts used in China are 8.8 and 10.9, while the high strength bolt strength bolts are only 10.9. The large hexagon head high strength bolt connection auxiliary consists of one bolt, one nut and two washers (each screw head and nut): the torsion-shear high strength bolt connection pair consists of bolt, nut and washer composition. When bolts, nuts and washers form connection pairs, their performance levels must match.
2. According to the connection mode, the high-strength bolts can be divided into three types: friction connection, tension connection and pressure connection. Both frictional and bearing connections are shear connections. The bolt friction connection transmits the shear force through the anti-sliding force between the plates, and the sliding between the plates serves as the limit state of its bearing capacity. This connection can be called a non-slip connection or a friction connection. Family contact. There are many types of pressure high strength bolts, including pretension or arbitrary 50% pretension, assembly knock, ordinary hole type: these are based on interlayer sliding. Normal method (i. e. load is limiting). Using this method to calculate the carrying capacity of high strength bolts is exactly the same as the ordinary bolt connection. The high strength bolt pull connection is the pull connection of the bolt rod along the axial direction.
3, the use of high-strength bolts
High-strength bolts are suitable for large-span houses, steel structure of industrial workshop, steel frame structure of high-rise building, bridge structure, heavy lifting machinery and other important structures. Depending on the connection types, there are three following types:
(1) The installation wipe type high strength bolt is suitable for the beam and column connection in the steel frame structure, the heavy crane beam connection in the industrial plant, the solid belly plate beam connection, the brake system and the important structure of bearing the dynamic load.
(2) Pressure high strength bolts can be used for shear connection in a static load structure that allows a small amount of sliding or indirectly bears dynamic load.
(3) When the tensile strength bolt is pulled, its fatigue strength is low, and the bearing capacity of the bolt can not easily exceed 0.6P under the dynamic load can easily exceed 0.6 P (P is the allowable axial force of the bolt). Therefore, it is only suitable for use under static load, such as compression flanged docking joints, T-type joints, etc.
High-strength bolt is a new type of steel structure connection mode developed after riveting connection, which has been developed into one of the main means of steel structure connection today.
1. Classification of the high-strength bolts
High strength bolts can be divided into two types: hexagonal head and torsion shear; 8.8,10.9,12.9 by performance grade. Currently, the high strength bolts used in China are 8.8 and 10.9, while the high strength bolt strength bolts are only 10.9. The large hexagon head high strength bolt connection auxiliary consists of one bolt, one nut and two washers (each screw head and nut): the torsion-shear high strength bolt connection pair consists of bolt, nut and washer composition. When bolts, nuts and washers form connection pairs, their performance levels must match.
2. According to the connection mode, the high-strength bolts can be divided into three types: friction connection, tension connection and pressure connection. Both frictional and bearing connections are shear connections. The bolt friction connection transmits the shear force through the anti-sliding force between the plates, and the sliding between the plates serves as the limit state of its bearing capacity. This connection can be called a non-slip connection or a friction connection. Family contact. There are many types of pressure high strength bolts, including pretension or arbitrary 50% pretension, assembly knock, ordinary hole type: these are based on interlayer sliding. Normal method (i. e. load is limiting). Using this method to calculate the carrying capacity of high strength bolts is exactly the same as the ordinary bolt connection. The high strength bolt pull connection is the pull connection of the bolt rod along the axial direction.
3, the use of high-strength bolts
High-strength bolts are suitable for large-span houses, steel structure of industrial workshop, steel frame structure of high-rise building, bridge structure, heavy lifting machinery and other important structures. Depending on the connection types, there are three following types:
(1) The installation wipe type high strength bolt is suitable for the beam and column connection in the steel frame structure, the heavy crane beam connection in the industrial plant, the solid belly plate beam connection, the brake system and the important structure of bearing the dynamic load.
(2) Pressure high strength bolts can be used for shear connection in a static load structure that allows a small amount of sliding or indirectly bears dynamic load.
(3) When the tensile strength bolt is pulled, its fatigue strength is low, and the bearing capacity of the bolt can not easily exceed 0.6P under the dynamic load can easily exceed 0.6 P (P is the allowable axial force of the bolt). Therefore, it is only suitable for use under static load, such as compression flanged docking joints, T-type joints, etc.