Data analysis of structural bolts and torsional shear bolts of large hexagonal angle steel

There are two sealing rings in the bolt connection pair of large hexagonal angle steel structure, one on both sides of the bolt head and nut; the high-strength bolt with torsion shear has only one sealing ring and one at the nut side. The large hexagon head high strength bolt is divided into 8.8 grade and 10.9 grade, while the torsion shear type high strength bolt is only 10.9 grade. Torque wrench is used for large hexagon angle structural bolts, and electric wrench is used for torsion shear type high strength bolts, and the box head can be broken.  
In the whole process of construction, the final tightening torque of large hexagon is not very good, and the average altitude is not conducive to tightening and inspection, while the excellent practical operation of torsion shear type is generally estimation. The distance between the torsion shear type high strength bolts is larger than that of the large hexagonal angle steel structural bolts. When the portal steel structure adopts blue plate connection, the consumption of twisted shear channel steel is 1-5% higher than that of large hexagon head channel steel, and the price of large hexagon head section steel is less than that of torsion shear channel steel.
Steel structure portal steel frame generally adopts large hexagon head, and double-layer and multi-storey buildings generally adopts torsion shear type. In addition, there is also a kind of electric wrench with large hexagon head. For example, the space between the big hexagon head bolts of the electric wrench structure should be relatively increased. In some cases, when the electric wrench can not be used in the construction of torsional shear bolts, large hexagonal angle structural bolts can be used. It can be tested according to the corner method, it is generally not easy to touch. Especially for some very large high-strength bolts, such as M33, M39, etc., this unique large bolt can not be completed if it can not be tested in a general way. Because the torque value of this bolt is very large, it can not be completed with a torque wrench. At this time, the perspective method can be used, but the premise is to carry out key experiments in high-strength bolt manufacturers. The common specifications and models of torsional shear high strength bolts are M16, M20, M22 and M24. The construction quality is very easy to ensure, but the quality of electric wrench used in domestic engineering construction is poor, and the price of imported single machine version is too high.

In addition, because the price of torsional shear bolts is higher than that of large hexagonal structural bolts, most of them are used for single-sided steel structure construction. In the whole process of project construction, the torque wrench must be regularly checked and corrected. If it is impossible to retest the torque index of large hexagonal angle steel structural bolts on the spot in the project, it is proposed to adopt the torsional shear type high strength bolts as far as possible to ensure the construction quality. In addition, the on-site engineering supervision staff must carry out inspection on the electric torque wrench applied, so as to prevent some installation teams from adopting countermeasures without common tools, which may lead to hidden dangers of construction quality and safety.  
Main products: steel structure bolts and nuts, high strength bolts and nuts, hexagon bolts, hexagon nuts, chemical bolts and nuts and other special-shaped parts.