1. The penetration direction of steel structure bolts shall be convenient for construction, and each node shall be neat and consistent. After the high-strength bolts are threaded in and tightened with spanners, the temporary bolts are removed and replaced with high-strength bolts.

2. The tightening of high strength bolts must be carried out twice. The first time is the initial tightening: the initial tightening is 60% – 80% of the standard axial force (i.e. the design pretension) of the bolt. The second tightening is the final tightening. When the final tightening is done, the quincunx clip should be screwed off.

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

4. Attention should be paid to the direction when installing the torsional shear high strength bolt: the washer of the bolt should be installed on one side of the nut, and the chamfered side of the washer hole should contact with the nut.

5. The bolts after initial tightening shall be marked for confirmation. In order to prevent missed tightening, the high-strength bolts installed on the same day shall be finally tightened on the same day.

6. The initial and final tightening should be carried out symmetrically from the middle of bolt group to all sides.

7. Due to the narrow space, the high-strength bolt wrench is not suitable to operate the parts. It can be installed by heightening the casing or using a manual wrench.

8. Torsion shear type high-strength bolts shall be completely screwed off, and the tail plum blossom clip shall be the end of final screwing, and no omission is allowed.