Electric wrench is mainly used for fastening high-strength bolts. Its purpose is to destroy the plum head of the high-strength torsional shear bolt. In order to understand the electric torque shear wrench, we must first understand the torque shear type high strength bolt.

　　高强螺栓按施工工艺分为:扭剪型高强螺栓和大六角高强螺栓。高强度扭剪螺栓一端为花键端，螺栓螺母一般为圆形(不需要用扳手固定)。

　　According to the construction technology, high-strength bolts are divided into: torsional shear type high-strength bolts and large hexagon high-strength bolts. One end of the high-strength torsional shear bolt is spline end, and the bolt and nut are generally round (no spanner is needed to fix them).

　　扭剪式高强度螺栓(TCB)的加捻过程:(理解“紧固轴力”)

　　Twisting process of torsional shear high strength bolt (TCB): (understand "tightening axial force")

　　削弱断面的剪切过程

　　Shear process of weakened section

　　同时将扭矩施加于被组装材料的内部拉应力，使其达到设计值(“拉紧轴力”)，材料相应的抗剪强度刚好使杆头截面弱化和扭转。

　　At the same time, the torque is applied to the internal tensile stress of the assembled material to make it reach the design value ("tension shaft force"), and the corresponding shear strength of the material just makes the cross section of the rod head weaken and twist.

　　分析表明，即使是扭转剪切螺栓也不是直接反馈螺杆内的预紧力值，而是由抗剪强度代替。测试项仍然不是直接项，并且存在替换错误。

　　The analysis shows that even the torsional shear bolt does not directly feedback the preload value in the screw, but is replaced by the shear strength. The test item is still not a direct item and there are replacement errors.

　　因此，为了保证扭剪螺栓的施工质量，有必要对螺栓切割时的“紧固轴力”进行测量。该值应符合预紧力的设计值。

　　Therefore, in order to ensure the construction quality of the torsional shear bolt, it is necessary to measure the "fastening axial force" when the bolt is cut. This value shall be in accordance with the design value of preload.

　　根据gb jgj-82 6.1.1的规定，在高强度螺栓连接副中，扭转-剪切高强度螺栓应具有一个垫片和一个母片。在接受扭剪式TCB时，注意杆头拧合合格。

　　According to 6.1.1 of GB jgj-826.1, the torsional shear high strength bolt should have a gasket and a mother plate. When accepting the torsional shear TCB, pay attention to the qualified screw in of the rod head.

　　扭剪作为大型六角升级版，其价格有点贵，施工、检验相对简单，优点明显。但国产产品受国标产品标准型号限制(仅10.9级，尺寸24M)。理解其核心原理的关键是掌握“扭矩系数”和“紧固轴力”两个概念。

　　As a large-scale hexagon upgraded version, torsion shear is a little expensive, relatively simple in construction and inspection, with obvious advantages. However, the domestic products are limited by the national standard product model (only 10.9 grade, the maximum size is 24m). The key to understand its core principle is to master the concepts of "torque coefficient" and "tightening shaft force".

　　扭剪式螺栓采用电扭剪式扳手结构，其根部采用前后扭杆直接通过“杆头”夹紧螺钉本身，因此在扭转时不会出现共转现象。本产品的设计思路是:当螺杆达到预紧值时，材料能承受相应的剪切力，设计并弱化梅花头根部截面，达到切割的目的。

　　The torsion shear bolt adopts the structure of electric torsion shear wrench, and its root adopts the front and rear torsion bars to directly pass through the "rod head" to clamp the screw itself, so there is no co rotation phenomenon during torsion. The design idea of the product is: when the screw reaches the pre tightening value, the material can bear the corresponding shear force, design and weaken the cross section of the root of the plum head, so as to achieve the purpose of cutting.