How should bolts be installed correctly

2023-06-19 15:47:15

When using two nuts, one thick and one thin, to prevent loosening, the thick nut should be placed on top, and most people use it in the opposite direction. Therefore, to prevent incorrect use, it is recommended to use two identical nuts.

Can I place the flat washer freely? In fact, the unmarked side should be in contact with the nut. The marked side of the nut needs to be exposed for easy tracking and inspection of the nut.

The bolt contact surface cannot be painted. Paint will increase the stress relaxation of bolts, which means that the pre-stress of bolts will decrease over time.

It is best not to use spring washers to connect bolts above grade 8 that require pre tightening. Experiments have shown that the anti loosening effect of spring washers in pre tightening bolts is relatively poor, and it can also lead to a rapid decrease in pre tightening force, which is not worth the loss.

The structure is connected by bolts, and when selecting bolts, the size of the bolts should not be less than M12.

6. When high-strength pre tightening bolts are tightened using the torque method, if the washer in contact with the nut rotates with the nut during tightening, this connection will fail because the bolt manufacturer ensures the frictional resistance between the nut and washer during the production of the bolt group, and the coefficient of friction between the washer and the connecting piece is unknown. Therefore, the corresponding relationship between tightening torque and pre tightening force is also unknown. Therefore, the bolt group needs to be replaced.

When tightening bolts, the speed of tightening the nuts should not be too fast, as tightening too fast will affect the friction coefficient between threads.

When bolts are tightened, they cannot be tightened to the final torque at once unless all bolts at the unified connection are tightened simultaneously.

When tightening bolts, the bolt manufacturer is responsible for lubricating high-strength bolts with high requirements, so there is no need to lubricate bolt components with high requirements and ensure the torque coefficient of the bolts.