Preload of high-strength torsion shear bolt - the strength bolt of steel structure is realized by tightening the nut. Torque method, angle method or the method of breaking the bolt tail are usually used to control the preload. At present, there are special wrenches to show torque Through the relationship between the measured torque and bolt tension, the applied torque reaches the necessary over tension value.
Angle method angle method is divided into two steps, one is initial tightening, the other is final tightening. In short, the initial tightening is generally that workers use an ordinary wrench to make the connected parts closely fit, while the final tightening is based on the initial tightening position as the starting point, and the final tightening angle is determined according to the bolt diameter and the thickness of the laminate.
Turn the nut with a torsion shear wrench. When it is screwed to the predetermined angle value, the tension of the bolt can reach the required pre tightening value. In order to prevent the high-strength bolt from changing the torque coefficient due to the influence of the external environment, the initial and final tightening should be completed in the same day. The stress characteristics of high-strength torsional shear bolts are the same as those of general high-strength bolts, but the method of applying preload is to control the value of preload by destroying the cross section of the bolt head notch.
Friction type high-strength torsional shear bolt connection completely depends on the friction resistance between the connected parts. The friction resistance is not only the preload of the bolt, but also depends on the surface treatment of the connecting element material and its contact surface determined by the following factors. After reading, I believe you have basically understood where high-strength bolts should be used and the correct operation and tightening.
In addition, the speed of concrete mixer truck is generally fast. In addition, the braking distance will become longer due to the body and heavy concrete, which are all the reasons for the frequent occurrence of accidents.
The above is the detailed introduction of the electric wrench for torsion and shear. I hope it will be helpful to you If you have any questions, please contact us We will provide you with professional service http://www.no2design.com