What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
leak-proof combined gasket relates to a gasket and solves the problem of short service life of the existing gasket. The combined gasket comprises: an O-shaped sealing ring, which is an annular sealing ring with an outer diameter of D and an inner diameter of E. The section diameter is A; the steel outer ring is a steel flat annular outer ring, which is sleeved on the outer surface of the O-ring, the inner diameter is F, and F=D, the thickness is B, B=0.785A ;The steel inner ring is a steel flat annular inner ring, embedded in the inner surface of the O-ring, the outer diameter is G, and G=E; the thickness is C, and C=B. When the O-ring in the combined washer is pressed by the bolt for sealing, it is positioned between the steel outer ring and the steel inner ring, and is protected by both of them, so that the tightening torque of the bolt can be reduced at least Double the sealing performance without reducing the sealing performance, extending the service life of the thread and reducing the production cost.
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.
Stamping die is a special process equipment for processing materials into parts in cold stamping processing, called cold stamping die. Stamping is to use the die installed on the press to apply pressure to the material at room temperature to make it produce Separation or plastic deformation to obtain the required parts of a pressure processing method, the technology generally used is to make corresponding holes and punches on the template, this method cannot meet the requirements for small batches and short delivery time products , the relative cost is relatively high, so a rivet die structure is required to improve the above problems.
Currently, the method of fixing objects on cement is with cement nails or expansion screws. Cement nails are objects made of hard alloy steel that look like iron nails, which are composed of nail tips and nail bodies. Cement nails are hammered into the cement. Cement nails are easy to drive in, but not removable. The expansion screw is composed of a large end screw, a slotted sleeve, a gasket, a spring washer, and a nut. When using, first drill a hole in the cement with an electric hammer, put in the expansion screw, and tighten the nut to make the slotted sleeve expand at the tail of the big tail screw, so as to fix the expansion screw on the cement. At this time, unscrew the nut to install a fixed object on the expansion screw. Although this method can be disassembled, an electric hammer is required for the first installation, which is inconvenient.
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