The Japanese say that "never loose" nuts are very popular all over the world. Some people say that China's high-speed rail is inseparable from Japan's nuts. I don't know, since the development of our country, the self-locking nuts have perfectly defeated the other party! Let's take a look at the strength of the nut, Japan boasts that it never loosens. "Never loose" means to fix any part or component without displacement or rotation, which means that there will never be any looseness during installation and disassembly, even if there is a slight deviation, it will not affect the overall performance . Developed by Hadlock Industries Co., Ltd., it is no exaggeration to say that countries around the world once relied on the "never loose" nut of this small Japanese factory.

However, the design principle of a nut with such a name is simple. It is used in pairs, a pair of nuts are designed to be convex, the convex nut is made by eccentric processing, and the concave nut is made of a normal center circle. This type of nut usually requires the male nut to be placed underneath and then the female nut installed. Because of the connection of these two different shapes, a special appearance is produced. This nut is what we usually call a "universal" nut. The universal nut is one of the members of the metal nut family. It uses the action between a hammer and a wedge to make the nut difficult to loosen, and then adds a hexagonal surface to the nut to make it difficult to loosen. Its structure is somewhat similar to the tenon-and-mortise structure in ancient buildings.

After the advent of Japan's "never loose" nut, it has been widely used on railways in China, South Korea, the United Kingdom and Poland. It has higher reliability and durability than traditional nuts in many aspects, and can be reused many times, so it is very popular with users. At present, this nut has become a standard product in Japan and around the world. In addition, the U.S. space shuttle launch pad, Japan's longest suspension bridge Akashi Kaikyo Bridge and the world's tallest free-standing radio tower "Tokyo Skytree" also use this never-say-die nut.

The point here is that this nut is not as good as people say it is, nor is it really "never loose".

Why did you say that? This is because the Japanese refer to nuts as "permanent magnets". The so-called "permanent magnet effect" is that when an object vibrates, its internal magnetic field lines change to generate a magnetic force, which keeps it in its original position. The nut mainly relies on the joint action of two nuts and uses eccentric pressure to fix the nut loose. However, nuts made with this principle will be affected by eccentric forces, making their overall service life short and requiring regular tightening and replacement. Generally speaking, Japanese "never loose" nuts need to be tightened every few months.

In addition, this kind of nut is not actually a Japanese patent. The research and development time of this kind of nut in my country is relatively long, but its use range is not very large, so there is no large-scale R&D and production. Plus the time, effort and expense of choosing imported products are much less than those of our own research and development, we also imported nuts for building high-speed rail. In other words, we import these nuts not because we can't produce them, but because of cost and other factors, we don't mass produce them. Now this kind of nut in Japan has been widely used in China's high-speed railway. And the Japanese call it the "never loose" nut. This can be seen from the degree of Japanese dependence on high-speed rail. Therefore, it is completely nonsense to say that our high-speed rail is inseparable from Japan's "never loose".

So, what is the content of nuts in my country now?

Many people may not know that my country's nut industry has reached the world's leading level. As early as 2002, my country developed a "never loose" self-locking nut, which is unique to China and is used in the extremely difficult situation of the Qinghai-Tibet Railway. This is the only nut that can be used in the braking system of high-speed trains in the world. And what our country has developed is a real "never let loose" because even if you screw it up, the nut won't move.

The self-locking nut is composed of a nut and a washer, and has the advantages of anti-loosening and anti-vibration. Self-locking principle: Since the bolts and nuts are connected in different ways, the self-locking devices are also different. At present, there are mainly two forms of self-locking bolts sold in the domestic market - hexagon socket screws and self-tightening screws. The nut and the gasket adopt a helical surface matching structure to achieve self-tightening force. When the nut is loose, the gasket will rub against the nut to generate friction, so as to achieve the effect of preventing loosening and breaking. Therefore, the self-locking nut can only be tightened, not loosened, and the nut can only be loosened by twisting the washer. In addition, the self-locking nut produced in my country also has a variety of helical surface supporting structures, which improves the stability of the nut, makes the stress distribution uniform, greatly improves the bearing capacity of the nut and the screw, and reduces the damage of the nut in use. In addition, the self-locking nut also has a strong active self-tightening force, which is much stronger than the Japanese "never loose" nut. Self-locking nuts also generate more reverse self-tightening force when turned in the opposite direction, making them super safe, even comparable to welding.

Of course, the advantages of my country's self-locking nuts do not stop there. But the most important thing is the reliability and safety in practical application. Because once the self-locking nut fails, the consequences are unimaginable. Therefore, special attention should be paid to the following issues when using self-locking nuts. As we mentioned earlier, Japan's "never loose" nut needs to be tightened every six months, while our self-locking nut does not need it at all, which is why we dare to use it on the plateau railway.

In addition, the self-locking nut developed in my country requires much less force to install and tighten than the Japanese "never loose" nut. Therefore, its tightening force does not decrease significantly compared to "never loose" during assembly. This is because the nuts produced in my country have good corrosion resistance and strong tensile strength. In addition, it also has certain hardness and toughness. It can be seen from this that the self-locking nut developed in China can be a "hung" Japanese "never loose" nut. Japanese "never loose" nuts are by no means a necessity in my country's high-speed rail manufacturing.

In contrast, Japanese nuts are indeed "inseparable" from China. In some large companies in Japan, the use of nuts accounts for more than half of the total product. Among them, HADOK Group occupies a large proportion. It is understood that most of the profits of Hardlock Industries in Japan come from China. Imagine how much profit this company will make once China stops importing nuts. In addition, my country has already started to produce self-locking nuts, and there is no need to go to Japan to import its own "never loose" nuts. Therefore, compared with China's demand, Japan's nuts are indeed inseparable from China.

In fact, between the Japanese nut industry and the Chinese nut industry, it is more about who needs who and who achieves, rather than who depends on whom. In addition, there is still a lot of room for development of various products independently developed in my country. As the saying goes: "Three people, there must be my teacher." What we need to do is to learn from others' strengths and make up for our own weaknesses. Only in this way can we continue to develop ourselves. We should learn from the valuable experience accumulated by Japanese companies in management. While importing foreign products, we can also learn from foreign high-quality and high-standard products, understand our own shortcomings, and learn from each other's strengths.