【Summary】What is an automotive fastener? This question is well answered. Retail components used in automobiles with a threaded coupling function are called automotive fasteners. Although automotive fasteners are not regulated as a special industry, they are an industry that requires high safety and quality standards.
What is an automotive fastener? This question is well answered. Retail components used in automobiles with a threaded coupling function are called automotive fasteners. Although automotive fasteners are not regulated as a special industry, they are an industry that requires high safety and quality standards. There are thousands of cars on the road and it would be terrible if a screw failed because of its quality, so the quality of automotive fasteners requires a pass rate of 100 per cent and does not allow even a single wire to have quality problems.
All car manufacturers, for the use of automotive screw standards, have carried out a scientific and reasonable design and experiments, the automotive screws purchased by the workers, will be its materials, heat treatment process, physical properties, salt spray time, size standards, fatigue data, etc., are subject to a long period of data archiving and analysis. Therefore, the production of automotive screws is not just like our regular industrial fasteners, which can be produced with qualification. In order to produce professional automotive screws, in addition to the simple ISO system certification, it is also mandatory to pass the TS16940 certification. Overall, the production of automotive screws is more demanding in terms of regulation and investment.
Among the automotive screws that we come into contact with on a daily basis, those used in electronic circuits are a little easier, the main problem lies in the coupling parts of the car. We know that the strength of the screws used in the car are in the 10.9 grade or above, and this high strength screws are prone to hydrogen embrittlement, if used in equipment, even if the screws break a, we replace it, the loss is not very terrible, but if the screws are broken because of hydrogen embrittlement, you think about it, the car is driving on the road, how dangerous it is not necessary for us to describe it.
We have always said that the screw hydrogen embrittlement is not controllable, and this statement in the car screw will not work, the car screw hydrogen embrittlement must be zero occurrence, so in the design drawings of automotive fasteners, there will be some warning notes, which is why the car screw requirements plating Dacromet more reasons, after all, or to control the hydrogen embrittlement does not appear.
In the use of automotive screws, the causes of hydrogen embrittlement caused by the plating, in addition to other can be solved, so the automotive screws in the plating requirements are also different from the plating of conventional screws, automotive screws after plating, the need for two hours of baking treatment, and control its hardness at 27 degrees. The automotive screw must be given a correct individual programme to operate according to its heat treatment conditions, and also ensure that the heat treatment staff are properly trained for the job.
Introduction to bolt strength classes
Strength grades are classified according to mechanical properties. According to the relevant standards, the bolt performance grade is divided into 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and more than 10 grades, of which 8.8 and above bolts made of low-carbon alloy steel or medium carbon steel and heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade number has two parts consisting of numbers, which indicate the nominal tensile strength value of the bolt material and the flexural strength ratio. For example.MORE +
The first is the punching of the head, where the head of the screw is punched out of the wire and the wire is cut. The second is thread rolling, where two files are used to thwart the threads on top of the previous process.MORE +
Performance grades for hexagonal flange bolts
The bolt performance grade is composed of two numerical parts, which indicate the nominal tensile strength value and the flexural strength ratio of the bolt material.MORE +
What are the common automotive fasteners
Generally we use most of the fasteners belong to the type of general-purpose parts, its standard type is still quite high, the common fastener parts are the following 12 kinds:MORE +