Bolt Fracture What is the cause, the cause of high strength bolt breakage?

1.Overload; 2.Improper tire reloading method leads to loosening of tire bolts, and unbalanced tire cutting bolts during driving;

3.The bolt holes of the tire steel rim are damaged or do not match the original car, and the force during driving does not meet the design value, resulting in the tire bolt being cut off;

4.Double-wheel clamp foreign body, driving for too long leads to bolt fatigue breakage;

5.The preload is too large and the bolt is broken;

6.The overall size of the tire exceeds the allowable size, resulting in the force on the tire bolt exceeding the design value;

7.Bolt quality problems, including: heat treatment, material, design and processing size, etc.

The loosening of threaded fasteners is not due to the fatigue strength of the bolt:

Threaded fasteners need only 100 times to loosen in a transverse vibro loosening test and 1 million times in a fatigue strength test. In other words, the threaded fastener loosens when it uses 1/10,000 of its fatigue strength, and we only use 1/10,000 of its maximum capacity, so the loosening of the threaded fastener is not due to the fatigue strength of the bolt.

The real cause of threaded fastener damage is loosening:

After the threaded fastener is loosened, a huge kinetic energy MV2 is generated, and this huge kinetic energy directly acts on the fastener and the equipment, resulting in damage to the fastener, and after the fastener is damaged, the equipment cannot work in a normal state, which further leads to damage to the equipment.

In fasteners that are subjected to axial forces, the threads are broken and the bolts are broken.

For fasteners subjected to radial forces, the bolts are sheared and the bolt holes are elliptical.

The selection of anti-loosening effect Youbi quiet thread anti-loosening method is the root of the problem

At present, the most advanced and effective anti-loosening method is the down's threaded fastener anti-loosening method.

The Down thread has both left-handed and right-handed threads. It can be mated with both left-hand and right-hand threads.

Two different types of nuts are used for the joint. The nut on the working bearing surface is called the fastening nut, and the nut on the non-supporting surface is called the lock nut. When using, pre-tighten the fastening nut first, and then pre-tighten the lock nut.

In the case of vibration and impact, the fastening nut will loosen, but because the loosening direction of the fastening nut is the tightening direction of the locking nut, the tightening of the locking nut just prevents the loosening of the fastening nut, resulting in the fastening nut can not be loosened.

Bolt breakage is not necessarily a strength issue.

The likelihood of bolt breakage is on the side of the Dona ruler.

First, there is a hole that can be dispersed, and the high energy is not strong enough; Digs.

Second, it is possible that the bolt itself is trapped, such as stress concentration;

Third, there may be problems with raw materials;

Fourth, it is possible that the heat treatment is not well treated.

Summary. 1. Ductile fracture;

In addition to high-strength bolts, ductile fracture is often accompanied by large plastic deformation.

Cause of nut clamp breakage.

Dear, I have summarized the following reasons for you:

1. Ductile fracture; In addition to high-strength bolts, ductile fracture is often accompanied by large plastic deformation.

2. Brittle fracture; When an impact load is applied, the screw undergoes brittle fracture; In particular, when there are defects such as segregation in the material and foreign matter, or improper heat treatment, or the crystalline particle size of the mild steel bolt is large, the bolt is prone to brittle fracture;

3. Fatigue fracture; 1.When the tightened bolt repeatedly bears the external fluctuating load (especially the tensile load) of the ruler load, the fatigue disturbance wheel fracture is prone to occur; The so-called fatigue failure, even if the size of the fluctuating load is much lower than the tensile strength of the material, it will cause damage to the material;

Dear, I hope it can help you!

This is a triangular tooth screw with a locking function. The possible causes of a broken screw are:

1. Hydrogen embrittlement fracture: If it is a C1022 material, it is generally carburized and heat treated, and the surface hardness is relatively high, and the core hardness is relatively low. It may be a problem of heat treatment, and the hardness of the core is high, resulting in increased brittleness; Even if electroplating is dehydrogenated, the risk of hydrogen embrittlement is still very large.

2. The deep groove leads to fragile head and neck joints: I feel that this reason is not very big.

3. The R angle of the head and neck junction is small: it is the same as the second one, which leads to the fragility of the joint.

Generally, if the above three aspects are well controlled, there is no problem with the use of this screw. I don't know where to use it, it is recommended to use C1035 material to make grade products, there will be no risk of hydrogen embrittlement.

It may be caused by quality problems, do not use too much force when doing it yourself, twist the gong wire to moderate strength, rely on your own feel to operate, and master the skills of the gong wire.

Hello, the screw can be divided into a water screw and a wall screw. The reasons for the fracture are: first, the diameter is too thin, the diameter of the screw is not calculated, the side pressure of the concrete is not calculated, the spacing arrangement of the screw is too thin, etc.; Second, the material of the screw does not meet the requirements, this is a problem of quality, I hope to help you, thank you.

The causes of screw fracture are as follows:

1.The screw itself is of poor quality.

2.The temperature of the barrel is set low, and the shear force on the rotation of the screw is too large.

3.The screw length-diameter ratio is not suitable and is big.

4.There is a problem with the screw mounting and fixing. Hua Hong answered.

5.The raw materials used have too hard metal or non-metallic impurities in them6The injection molding machine starts cold, and the viscosity of the raw material in the barrel is too high.

The impact toughness of the bolt is enough, but there may be shear force when used, and the shear strength exceeds its load, the bolt sometimes can not be used as a pin, the end face is flat, see if it is stressed shear, see how this section looks like rust.

First, the material may be informal and unqualified; Second, the heat treatment is unqualified, and the stress concentration occurs, which is easy to fracture.