Installation requirements for high-strength bolts

Installation requirements for high-strength bolts

High-strength bolts are a kind of high-strength screws and are standard products. Generally speaking, the load of high-strength bolts is greater than that of ordinary bolts of the same specification. Therefore, the application range of high-strength bolts is relatively wide. High-strength bolts are mainly used in steel structure projects to ensure the stability of the project. So what should be paid attention to during installation? Aozhan Hardware will introduce it to you.

Installation requirements for high-strength bolts:

1. When assembling the high-strength bolt connection pair, the side with the round surface of the nut should face the chamfered side of the washer. When assembling the large hexagonal high-strength bolt connection pair, the chamfered side of the washer under the bolt head should face the bolt head.

2. When installing high-strength bolts, the friction surface of the component should be kept dry, so it should not be worked when it rains.

3. When tightening high-strength bolts, only torque is allowed to be applied to the nut. However, tightening is also allowed in places where space is limited.

4. When installing high-strength bolts, it is strictly forbidden to force the bolts (such as hitting with a hammer). If it cannot pass freely, the hole should be repaired with a tap, and the maximum diameter of the hole after repair should be less than 1.2 times the bolt diameter. When repairing the hole, in order to prevent iron filings from falling into it, all surrounding bolts should be tightened before reaming the hole, and then sealed. It is strictly forbidden to gas cut and expand the hole.

5. The tightening of high-strength bolts is divided into initial tightening, compound tightening and final tightening. The initial torque is 50% of the construction torque, and the first bolt is tightened symmetrically with a quick wrench. The compound torque is equal to the initial torque, and the tower connection bolts are tightened with a hydraulic wrench in the order of symmetrical shapes. To prevent omissions, color marking should be used for high-strength bolts after initial tightening, compound tightening and final tightening. After inspection, mark the high-strength bolts with another color.

6. When the high-strength bolts are initially tightened, re-tightened and finally tightened, the bolts at the connection should be tightened in a certain order, and the center sequence of the bolt group is generally tightened outward.