Detailed Introduction Of Different Fishbolts

Fishbolt is a product widely used in heavy industry. It is very convenient to use and relatively low in price. High-strength fishbolts can be produced by using low-carbon alloy steel or medium-carbon steel and heat-treated. The most common fish bolts.
In terms of material, high-strength fishbolts are made of high-strength materials. The screw, nut and washer of high-strength bolts are all made of high-strength steel, and ordinary bolts are usually made of Q235 steel. From the comparison of strength grades, high-strength fishbolts are widely used, and two strength grades of 8.8 and 10.9 are commonly used, of which 10.9 is the majority. The strength grade of ordinary fishbolts is much lower, generally 4.8 and 6.8. From the comparison of the force characteristics, the high-strength fishbolt exerts pre-tension and transmits external force by friction. Ordinary fishbolt connection relies on the shear resistance of the bolt rod and the pressure bearing of the hole wall to transmit the shear force. When the nut is tightened, the pre-tension force is very small, and its influence can be ignored.
In terms of use, ordinary fishbolts can be reused, but high-strength fishbolts cannot be reused. High-strength fishbolts are prestressed bolts. The friction type uses a torque wrench to apply the specified prestress, and the pressure type unscrews the torx head. Ordinary fishbolts have poor shear resistance and can be used in secondary structural parts. Ordinary fish bolts only need to be tightened. High-strength fishbolt connection has the advantages of simple construction, good mechanical performance, removable, fatigue resistance, and no loosening under dynamic load. It is a promising connection method. High-strength fish bolts are tightened with a special wrench to make the bolts produce a huge and controlled pre-tension force, and the same size pre-stress is produced on the connected parts through the nuts and backing plates. Under the action of pre-pressure, a large frictional force will be generated along the surface of the connected parts.