The survey of the visit and investigation of 13 domestic automobile fasteners, the company has adopted both TS16949 certification. An average of one car about 1,500 fasteners, bolts per vehicle assembly of the total time of about 2.5-3.2 h. Fasteners that the variety and quality of the host level and have a major impact on vehicle quality.

       In this paper, high-strength thread fasteners from the production process of manpower, high-strength thread fasteners on the domestic and Availability of quality management for analysis.

       1. Threaded fasteners high-strength products Process

       High-strength thread fasteners production process for the conversion of raw materials �� cold heading forming �� thread processing (silk or roller Roll) �� heat treatment �� surface treatment �� separation package, 10.9 more than the general roll wire after heat treatment process.

       2. Automotive fasteners materials

       High strength bolts commonly used for the 8.8 grade steel bolts with 35 steel, 45 steel, ML35 steel; 10.9 bolts with 35 CrMo; 40Cr; 12.9 bolts with 35 CrMo, 42CrMo, SCM435.

       Automotive standards of domestic materials used mainly in Baoshan Iron and Steel Company production of materials mainly in the domestic passenger car tyres, commercial vehicle engines and other special high-strength steel fasteners of the market share higher. At present, the Baoshan Iron and Steel Company has become the FAW, Dongfeng, Shanghai Automotive companies such as special steel for the specified standard parts manufacturers.

       10.9 and 12.9 Engine fasteners imported materials mainly from Kobe, Japan, the Japanese Nippon Steel, POSCO and other Korean companies. Hardenability imported materials, and high-purity, the assembly stability. Higher than the domestic cost of about 15 to 20 percent.

       At present, the domestic production of high strength bolts special quality of the best companies in Shanghai from raw materials (import), cold upsetting process, heat treatment, surface treatment in accordance with all of the Japanese joint venture's production processes, quality and stability, but the high cost. The largest auto parts company standards »» Dongfeng steam standard fasteners used on passenger cars is also the choice of materials mainly imported materials, commercial materials selection Baoshan Iron and Steel Company.

       Fasteners with domestic hot-rolled state is the basic raw materials, like Japan and other countries production of steel fasteners are basically direct cold heading, and users without pretreatment, from areas to reduce costs.

       Failure of firmware common form of failure assembly longer, fatigue fracture and delayed fracture.

       3. Cold Heading forming processing and thread (or wire roller Roll, tapping)

       Threaded fasteners in addition to the quality of materials, equipment and thread forming processing equipment and die (and their production technology and equipment) is to guarantee the quality of its key elements. Especially in large quantities and more varieties available under the requirements of high-precision machining of automotive fasteners, how to ensure the consistency of product defects and the prevention of fasteners is one of the problems facing the production.

       The company's cold-heading equipment and thread processing equipment, accounting for about 40 percent of domestic equipment, the Taiwan equipment accounted for 50 percent and imports (Europe and the United States, Japan) equipment accounted for about 10 percent of defects are common size and shape of tolerance ultra-poor , Fold over his head, heading off thread-line, the Department of teeth, such as cracks and wrinkles.