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Customized 12.9-grade black half-tooth hex bolt external hexagon screw 3/4

author:[email protected] Click:5972end source: time:2023-08-31 13:02:27

Summary of information:We have more than ten years of production experience in the screw industry, the main products are: GB70.2 screws, Philli...

At present, more rivets are used on car tires. Due to the long-term bumps of the car, traditional equipment is prone to loosening during the use process, which affects safety. The above problems need to be improved on traditional equipment, so how to design a Rivets on car tires, this becomes a problem we need to solve.

At present, shaft retaining rings are mainly divided into three categories: elastic retaining rings for shafts, flattened wire retaining rings for shafts, and wire retaining rings for shafts. Among them, the spring retaining ring for the shaft is generally installed with circlip pliers, and the flattening wire retaining ring for the shaft and the wire retaining ring for the shaft are generally installed with a sharp screwdriver or needle-nose pliers. The defects and deficiencies of these two methods will be discussed in detail below: First, the above two installation methods require the operator to use a large force to open the retaining ring, which is more laborious; For the installation of the flattened steel wire retaining ring for the shaft and the steel wire retaining ring for the shaft, because the wire retaining ring has low elasticity and has no force point, it is very easy to cause the retaining ring to break or the installation tool to slip during the installation process. Higher skills and experience can be competent for the installation of wire retaining rings.

The drawing process has two purposes, one is to modify the size of the raw materials; the other is to obtain basic mechanical properties of the fasteners through deformation and strengthening. For medium carbon steel, medium carbon alloy steel also has another purpose, that is, to make the wire rod. The flaky cementite obtained after controlled cooling is cracked as much as possible during the drawing process to prepare for the subsequent spheroidization (softening) annealing to obtain granular cementite. However, some manufacturers arbitrarily reduce the drawing in order to reduce costs. The excessive reduction rate increases the work hardening tendency of the wire rod, which directly affects the cold heading performance of the wire rod. If the distribution of the reduction ratio of each pass is not appropriate, it will also cause torsional cracks in the wire rod during the drawing process. In addition, if the lubrication is not good during the drawing process, it can also cause regular transverse cracks in the cold drawn wire rod. The tangential direction of the wire rod and the wire drawing die is not concentric at the same time when the wire rod is rolled out of the die, which will cause the wear of the unilateral hole pattern of the wire drawing die to aggravate, make the inner hole out of round, and cause uneven drawing deformation in the circumferential direction of the wire. The roundness of the steel wire is out of tolerance, and the cross-sectional stress of the steel wire is not uniform during the cold heading process, which affects the cold heading pass rate. During the drawing process of the wire rod, the excessive surface reduction ratio will deteriorate the surface quality of the steel wire, while the too low surface reduction ratio is not conducive to the crushing of the flaky cementite, and it is difficult to obtain as much granular cementite as possible. , that is, the spheroidization rate of cementite is low, which is extremely unfavorable to the cold heading performance of the steel wire. For the bar and wire rod produced by the drawing method, the partial surface reduction rate is directly controlled within the range of 10%-15%.

hand screw is a screw with a plastic head, and the user fixes the hand screw by turning the plastic head by hand. At present, a hand-tight screw is disclosed in the market publication number CN202203253U, which includes a plastic head and a screw rod, the plastic head and the screw rod are connected together, and the height of the plastic head is higher than that of ordinary screws, and the height is 3 cm. The screw of the hand screw is fixed in the plastic head by glue. After a period of use, the aging of the glue leads to the loosening of the screw and the plastic head. When the plastic head is stressed, the screw rod comes out of the plastic head, which affects the normal use of the hand screw.

There is a standard for the outer hexagon bolt standard, which is a grade standard, which is divided into grade 4.8 and grade 8.8. These two levels are used a lot in the market. Especially grade 4.8 hex head bolts. Because it is much cheaper than 8.8 hex bolts. Of course it is more widely used. But for demanding products. Because of its high requirements in various aspects such as hardness. This requires the use of 8.8 hex bolts. Grade 8.8 hex bolts are harder in terms of hardness and screw torque. It is safer to use the product. Tighter and more stable.

We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: GB carbon steel galvanized bolts, national standard raw material small yellow croaker plastic screws, elastic spring washers, round shaft rod axles and other products, we can provide you with The right fastener solution for you.

black teeth

Made to order 12.9


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