Why Does The ANSI B18.2.1 Bolt Break?

During the mutual meshing of the two threads, the actual torque parameter value will appear to be discrete, and the friction effect of the two threads will become more important. If the coefficient of friction of the thread is not fully considered, it is wrong to look at the torque parameter completely. If the coefficient of friction of the thread is large, the torque parameter should be reduced and vice versa. When is the value of the friction coefficient small? In some environments, the bolts will be coated with talc. At this time, the friction coefficient is lowered due to lubrication, which is common in many factories. The third type of high-strength, strong fracture is the fracture that occurs during fatigue use. The ANSI B18.2.1 bolt used in fatigue did not show any problems before breaking, so it was difficult to protect. Most of the fatigue fracture position appeared at the intersection of the bolt head and the screw and suddenly appeared in a static state. Due to the high added value of ANSI B18.2.1 bolts, in order to save the cost of the enterprise, ANSI B18.2.1 bolts will be reused indefinitely, and this problem occurs when the frequency of use exceeds its fatigue factor. It is rarely necessary to periodically inspect ANSI B18.2.1 bolts. There is also a break without fastening. You may ask, I did not tighten it, how can it break? It is well known that when ANSI B18.2.1 bolts and nuts are not fully tightened, there is a lot of room for movement. Let us give an example: two drill rods are bolted through ANSI B18.2.1 and then drilled on the ground. If the bolt is not tightened during drilling and the torque is large, it is a drill rod that drives the drill pipe. When the force is transmitted to one of the drill pipes, the bolts are not tightened and there is a lot of room for movement. The power of the air is transmitted to the bolts, and the bolts cannot withstand this. If your torque is too great, it will break. Another issue is the quality issue. For example, if the material fails or the heat treatment process fails, these are formed. This is a quality-related issue that can be easily resolved as long as the production and material procurement processes are controlled.