Hex Steel Nut Reusability
Application of Hexagon Nuts in Construction Machinery
Construction machinery is characterized by: the engine power, working conditions, by the impact load, the corresponding strong vibration, the general bolt and nut under the impact of vibration will be loose off. In order to prevent the failure of the fasteners, the various manufacturers were supernatural powers, and some use of preset torque nuts, and some use flattened nuts, and some use of chemical coating.
These methods have played a certain anti-loose effect, but they have two common weaknesses: First, the re-use of poor, some one-time, up to only 4-5 times; second, maintenance is not convenient, loaded, A lot of energy, and, chemical coating pollution of the environment, the construction of the workers also cause personal injury.
With the lock nut, not only can play a good anti-loose effect, and re-use performance is good, easy assembly and disassembly, and gradually used in the construction machinery of the key parts of the current construction machinery used to tighten the nut The following parts:
· Mixer, crane: bracket connection, reducer seat, tug and other parts.
· Vibratory roller: Coupling, engine universal joint.
Excavator: rotary support, track wheel, broken hammer.
· Bulldozer: track wheel.
Loader: drive shaft, main drive differential, large screw umbrella.
Is there any special requirement for bolts when using hex nuts? No, as long as the bolts meet the national standard can be. Bolt thread accuracy must ensure that 6g or more, cusp decarburization should be within the scope of national standards.
In this special note: thread precision 6g and tip decarburization, not a national standard beyond the special requirements, the commonly used bolt national standards, the surface treatment before the thread accuracy requirements are 6g. Cusp decarburization is also required by the national mechanical performance standards. The reason why we emphasize these two points is because:
A. If the thread diameter is less than 6g or the tip is decarburized, the tightening performance of the hex nut will be reduced and the serious person will be lost.
B. Many bolt manufacturers and users in the test thread, only the thread ring inspection, when the pass, only check that qualified qualified thread, in fact, this is not complete. Because the thread ring gauge only check the thread diameter, and did not check the thread diameter. So the test of the thread not only need to use the pass, but also need to use calipers (micrometer) test thread diameter. Only pass through, only the ring gauge inspection qualified, while large diameter inspection is also qualified thread is qualified thread.