Bai torsion shear type high strength bolt connection pair for steel structure is mainly used in industrial and civil buildings, highway and railway bridges. For tower, pipe support, hoisting machinery and other occasions where friction type connection of high strength bolt is required. It is characterized by an extra dodecagonal body at the end of the bolt.

安裝時，須用特制的電扳手，其上下有兩個套筒頭，一個套在螺母的六角體上，另一個套在螺栓的十二角體上。擰緊時，對螺母施加順時針力矩，對螺栓十二角體施加大小相等的逆時針力矩，使螺栓的末端與十二角體之間連接頸部承受扭剪，頸部剪斷為止，則安裝完成。這種扭剪型高強度螺栓為一次型使用的緊固件，安裝后一般不予拆卸。

During installation, a special electric wrench must be used. There are two socket heads on the top and bottom, one on the hexagon of the nut and the other on the dodecagonal body of the bolt. When tightening, apply clockwise torque to the nut and counter clockwise torque of equal size to the dodecagonal body of the bolt, so that the connection neck between the end of the bolt and the dodecagonal body is subject to torsional shear, and the installation is completed until the neck is cut off. This kind of torsion shear high strength bolt is a kind of one-time fastener, which is not disassembled after installation.