Method for installing bolts in steel structures

Method for installing bolts in steel structures

1. The direction of penetration of steel structure bolts should be based on convenient construction, and each node should be neat and consistent. After inserting high-strength bolts and tightening them with a wrench, remove the temporary bolts and replace them with high-strength bolts.  

2. The tightening of high-strength bolts must be carried out in two stages. The first time is initial tightening: the initial tightening is tightened to 60% to 80% of the standard axial force (i.e. design pre tension) of the bolt. The second tightening is the final tightening, and during the final tightening, the torshear type high-strength bolts should have the plum blossom clamp head removed.  

3. After a construction section is completed and the steel structure forms a stable frame unit, high-strength bolts are installed.

4. When installing torsion shear high-strength bolts, attention should be paid to the direction: the washer of the bolt should be installed on one side of the nut, and the chamfered side of the washer hole should be in contact with the nut.

5. The bolts that have been initially tightened should be marked for confirmation. To prevent missing tightening, the steel structural bolts installed on the same day should be completely tightened on the same day.

6. The initial and final tightening should be tightened symmetrically from the middle of the bolt group to the surrounding areas.

7. Due to the narrow space, high-strength bolt wrenches are not suitable for operating parts, and can be installed with raised sleeves or manual wrenches.

8. Twist shear type high-strength bolts should be completely unscrewed with the tail plum blossom clamp head as the final tightening, and should not be omitted.