Service HotlineFor a long time, the rivets used in general riveting, especially the ordinary rivets and bolts and other fasteners commonly used in steel structures such as vehicles and bridges, have low connection reliability, especially under alternating load and impact conditions. Looseness is easy to occur, the maintenance cycle is short, and the maintenance cost is high in the later period, which cannot meet the requirements of railway freight.
The maximum unscrewing torque of the lock nut is affected by many factors. For the research on the low-cycle fatigue performance of the lock nut, the pitch diameter of the thread, the helix angle and the bevel angle of the thread remain unchanged. Only the maximum elastic restoring force FNmax and the equivalent friction angle ρe of the thread piece will appear to a certain extent after repeated use. Change. Therefore, it is only necessary to analyze the variation law of the maximum unscrewing moment when the lock nut is subjected to cyclic load from these two aspects.
Advanced bolts are the foundation of high-end machinery manufacturing, and their role can be called four ounces. On the surface, the output value of bolts only accounts for a few percent of the machinery industry. In essence, the added value it brings to key components and equipment is much higher. Over the years, after the continuous double-digit growth of Chinese bolts, the bolt industry experienced negative growth in 2012, down about 1.5% year-on-year, mainly due to insufficient market demand, especially after the bolts suffered from international anti-dumping, export sales declined. situation. [1] The competition in the bolt market is fierce, and it is moving towards brand management. In the past 10 years, the development speed of China Bolt has attracted the attention of the world, which surprised the developed countries, but also made them discover a new type of big market, and multinational companies filed in. When domestic bolt companies suddenly feel that it is so difficult to survive in the market, powerful competitors have blossomed everywhere. In today's Chinese bolt market, some small and medium-sized bolt enterprises manufacture a large number of common standard parts, which does not really bring core competitiveness to the enterprise, but is subject to changes in raw materials, labor costs and other conditions. From 4.8 to 6.8 low-strength bolts, or 8.8 to 12.9 high-strength bolts, the production technology level of Chinese bolts will be basically close to the world's advanced level, mainly ordinary standard parts and low- and medium-grade special and special-shaped bolts, with large quantities Inexpensive. It can be concluded that low-grade products flood the dominant market, a small part of high-grade, high-precision, high-strength bolts still need to be imported, and the difference between the unit price of products imported and the bid price is about 6 times or more. It can be seen that China's bolt industry is still a developing industry, big but not strong, fat but not strong, and the gap with the United States, Japan, South Korea and Taiwan, my country, and lack of technical services to solve mechanical tightening. A solid solution to realize the digitalization of products, design, manufacturing and management, and the greening of products and manufacturing processes. It is understood that the development of Chinese bolts is under increasing pressure from resources and the environment. An important way to alleviate resource constraints is to develop green manufacturing. The development of bolts will continue to be actively promoted in the direction of brand management for a period of time in the future, and promote the development of bolt projects in all directions. [1] In terms of products, mid-to-high-end products will accelerate the localization of quality research and development. The whole process from design, manufacturing, packaging, transportation, use to end-of-life treatment must consider the least waste, the lowest emissions, and the high resource utilization rate. And the environmental impact is minimized, so that the corporate benefits and social benefits are coordinated and optimized. [1] In terms of circulation, explore various value-added service models to bring value and benefits to customers. From providing a single set of bolts to providing mechanical fastening solutions, customized services, remote monitoring, etc., the proportion of services in the sales revenue of bolt manufacturers will gradually increase. [1] Corporate restructuring is a trend, and strategic alliances seek development. At present, the low industrial concentration of China's bolt enterprises has seriously restricted the improvement of China's bolt competitiveness. The market opening over the years has not brought the core technology. In view of the above situation, the reorganization and strategic alliance between enterprises is a major trend. China's bolt industry must conform to this trend and trend, strengthen strategic cooperation between enterprises, and improve the overall competitiveness of China's bolts. China's growth in the field of bolt core technology lacks breakthroughs. At the same time, the living space of low-end products is getting smaller and smaller, and foreign capital through localized enterprises also has considerable cost advantages, coupled with the advantages of technology brands, and began to enter the market space of the original independent brands.
Earless retaining ring (known as Constant Section Rings abroad) is also called constant section retaining ring, because the cross section is equal, and there is no ear part protruding from the traditional stamping retaining ring, so it is called earless retaining ring. Earless retaining ring and spiral retaining ring have similarities in production, processing and use characteristics. They are both flattened and wound by steel wire. After heat treatment and surface treatment, they have good elasticity and toughness. Earless retaining ring is divided into two types: shaft use and hole use, and there are various forms of tail ends to choose from. The application of earless retaining ring is the same as that of traditional C-type retaining ring, which is widely used in hydraulic parts assembly, valves, instruments, various lock core components, needle roller bearings, pulleys, connectors, quick connectors and other mechanical assemblies.
1. Ordinary outer hexagon - widely used, characterized by relatively large tightening force, the disadvantage is that there must be enough operating space during installation, and adjustable wrench, open-end wrench or glasses wrench can be used during installation, all of the above wrenches require a large amount of space. operating space. 2. Cylindrical head hexagon socket - is the most widely used of all screws, because it has a relatively large tightening force, and can be operated with a hexagon wrench. It is very convenient to install and is used in almost all kinds of structures. The appearance is more beautiful and neat. The disadvantage is that the tightening force is slightly lower than the outer hexagon, and the inner hexagon is easily damaged due to repeated use and cannot be disassembled. 3. Pan head inner hexagon - rarely used mechanically, the mechanical properties are the same as above, mostly used in furniture, the main function is to increase the contact surface with wooden materials and increase the ornamental appearance. 4. Headless inner hexagon - must be used in certain structures, such as the top wire structure that requires a large top-tight force, or where the cylindrical head needs to be hidden. 5. Countersunk head hexagon - mostly used in power machinery, the main function is the same as the inner hexagon. 6. Nylon lock nut - a nylon rubber ring is embedded in the hexagonal surface to prevent the thread from loosening, and it is used on strong power machinery. 7. Flange nuts - mainly play the role of increasing the contact surface with the workpiece, mostly used in pipes, fasteners, some stamping parts and casting parts. 8. Ordinary hex nut - the most widely used and one of the most common fasteners.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: wave-shaped washers, screw anchor screws, rivet caps, plastic insulation support columns and other products, we can provide you with suitable fastening products piece solution.
