Recently, BMW has decided to recall a total of 232,000 related vehicles due to possible loosening or rupture of the bolts on the engine casing of some of its models. In recent years, cases of bolt recalls abound, bolts have become the smallest parts of the car can not be ignored. In the past interview process, some parts companies reported to reporters that few domestic fastener companies have the ability to produce high-strength bolts. Many high-strength bolts used in some key positions such as engines and chassis rely on imports. So, what is the strength of domestic bolt manufacturers? Do high-strength bolts have to be imported? Some high-strength bolts can be purchased domestically In general, bolts are classified into more than 10 grades ranging from 3.6 to 12.9 according to their nominal tensile strength and yield ratio. There are also significant differences in requirements for use in different areas. Chen Kun, head of the marketing department of Fasteners Automotive Parts Co., Ltd., told the reporter: “The car needs to use thousands of bolts, most of which are bolts of grade 8.8 and above, and bolts of grades 10.9 and 12.9. It can be called a high-strength bolt." Chen Kun uses engine bolts as an example to show that the bolts of the peripheral parts of the fixed engine have relatively low technological requirements, and ordinary bolts can meet the requirements. We often say that the high-strength bolts are mainly related to the strong components in the engine. For example, the flywheel bolts and connecting rod bolts must be 10.9, while the engine cylinder head bolts must be 12.9. The reporter interviewed a number of engine and car chassis related companies and asked about the purchase of high-strength bolts. These companies all said that high-strength bolts are not completely dependent on imports, independent brand companies are more willing to purchase domestic high-strength bolts, and joint ventures have gradually localized various bolt products to save costs. Chen Kun said that FOGO Fasteners has invested heavily in the development of a variety of 10.9-rated high-strength bolts for the VW EA211 engine. The matching standard is the same as in Germany. There are two types of mass production. Liu Kai, deputy general manager of Jiangxi Isuzu Engine Co., Ltd., said that the high-strength bolts of Isuzu Diesel have been purchased domestically and their procurement standards are consistent with the Isuzu Japan procurement standards. Sun Jingyu, Deputy Director of Quality Control Department of Qingte Group Co., Ltd., told the reporter: “The high-strength bolts used by Qingte Axle are not all imported. Some domestic fastener companies can also meet our process requirements.†The strength of domestic enterprises is still lacking “High-strength bolts require high manufacturing processes, especially high-strength bolts for vehicles, and any flaws will seriously affect the safety of driving.†Chen Yuanzhi, director of the International Department of China Automobile Industry Association, told reporters. Chen Yuanzhi stated that some fastener companies in China have the technology to develop high-strength bolts and can manufacture high-strength bolt samples. However, if high-volume production is difficult to guarantee the quality of each product, the main reason is that the product consistency does not meet the batch requirements. In addition, the domestic advanced alloy material is insufficient or there is no better material available. Therefore, some high-strength bolts still rely on imports. It is understood that the domestic general fastener companies can supply 8.8 bolts, and a lot of companies can mass produce 10.9 bolts, but there are not many companies that can produce 12.9 bolts. Chen Kun said that in fact, there are only about 5 fastener companies that have the ability to produce high-strength bolts at the same time and can do well in the industry and are recognized by the industry. It is noteworthy that this only a few companies also include joint ventures and wholly foreign-owned enterprises. According to the analysis, domestic companies have insufficient incentive to develop high-strength bolts. Chen Kun said that compared with ordinary bolts, the profit of high-strength bolts is not obvious, and with the large investment in the previous period, some small-sized companies may be able to make up for the high-strength bolts. The requirements for high-strength bolts vary from one auto company to another. This makes it more difficult to match this product, the cycle becomes longer; joint venture brands are very cautious about localization of high-strength bolts, localization will only choose the companies within its supporting system, domestic fastener companies rarely have matching opportunities. The production chain can not escape imports Although some high-strength bolts can be selected for domestic procurement, this appears to be a domestic fastener company has a certain degree of production strength, but in fact each high-strength bolt production process is difficult to separate from imports. Chen Kun said that the difficulties in the production of high-strength bolts lie in the following aspects: The cold heading process requires high product tolerances, which requires more sophisticated production equipment. These cold heading equipments must be imported from abroad or imported from Taiwan. Product hardness uniformity depends on the heat treatment process, high-end heat treatment furnace also needs to be imported; product surface treatment is also the key, and the required solution is also introduced overseas. The huge investment in equipment purchases has determined that some small fastener companies cannot join the ranks of high-strength bolts. Chen Kun said that Fool Fasteners has developed high-strength bolts for the VW EA211 engine for two years, investing tens of millions of dollars in the installation of general-purpose equipment, special heat treatment furnaces for car fasteners, and a series of testing equipment. The final product must also be tested and certified by a foreign agency. The raw materials for high-strength bolts are also inseparable from imports. It is understood that China's automotive fastener materials based on materials produced by Baosteel Group, many domestic vehicle companies to Baosteel as a designated manufacturer of special standard steel. A small number of high-strength bolt raw materials with special needs need to be imported from Japan and South Korea. "This huge investment is because we are aiming at the localization of high-strength bolts for domestic vehicle companies or domestic procurement. Although there will not be a surge in demand in the short term, this demand will exist for a long time," said Chen Kun. Sheet Metal Deburring Machine,Sheet Metal Polishing Machine,Sheet Metal Chamfering Machine,Flat Sheet Metal Deburring Machine Wuxi Taohua Machinery Technology co.,Ltd , https://www.wxblossom.com