The hexagon flange bolt is very popular nowadays. To […]
The hexagon flange bolt is very popular nowadays. To better use this equipment, we must use it reasonably in the selection process of preload.
In the assembly of professional bolts and fasteners, standard wrenches are generally equipped. Different diameter bolts use different length wrenches. The length of the wrench is about 15 times the bolt diameter. On this basis, professional mechanical tools can be used. Reflecting the accurate tightening torque and achieving a quantifiable pre-tightening force is particularly important to some key and important parts. Once a large-size longs wrench is used to tighten a small-size bolt, it will often cause over-tightening, damaging the part itself and making the entire connection structure fail.
When tightening the nut, two or more parts is compressed, the part itself is compressed, just like the compression deformation of spring, the contact surface between the nut and bolt and the assembly part will generate a lot of force, this The force will cause the bolt to undergo tensile deformation. The calculated stress is 1.3 times the simple axial tension.
When the tensile stress generated by the bolt exceeds the strength limit of the material, the bolt is broken. It is very unscientific for mass-produced products to tighten bolts only through the experience of the operator. When tightening small bolts with long wrenches, you should pay more attention to the pre-tightening force to avoid excessive pre-tightening.