1. Torque method

依据扭矩M与预拉力成正比的闭系,先用一般扳手将螺帽发端拧紧,而后采取可显现扭矩值的扳手拧至决定的扭矩值。

According to the closed system in which the torque M is proportional to the pretension, first tighten the nut with a general wrench, and then use a wrench that can show the torque value to the determined torque value.

2、转角法

2. Angle method

依据板层间密切交触后,高强度螺栓的转化角度与螺栓的预拉力成正比闭系决定的一种方式。紧固时,先用短扳手将螺帽拧至没有转化的位子,而后再用长扳手将螺帽拧至决定位子,以到达预拉力。

According to the close contact between plates, the transformation angle of high-strength bolts is directly proportional to the pretension of bolts. When tightening, first screw the nut to the position without conversion with a short wrench, and then screw the nut to the decision position with a long wrench to reach the pre tension.

3、拧断螺栓尾部

3. Unscrew the bolt tail

用于扭剪型高强度螺栓,此螺栓有一特制的尾部。紧固时,用扳手套住螺栓和螺栓尾部,一个套筒正转,另一个套筒回转,在螺帽拧紧到必定水平时,螺栓尾部拧断。因为螺栓尾部的槽口深度是按拧断扭矩和预紧拉力之间的闭系决定的,所以拧断时便到达相应的预拉力值。

It is used for torsion shear high-strength bolt, which has a special tail. When tightening, use a wrench to cover the bolt and the bolt tail. One sleeve rotates forward and the other sleeve rotates. When the nut is tightened to a certain level, the bolt tail is broken. Because the notch depth at the tail of the bolt is determined by the close relationship between the screwing torque and the pre tensioning force, the corresponding pre tensioning force value will be reached when screwing off.