Service HotlineStandard parts are commonly used parts, which are widely used in various mechanical structures. Among them, the T-track bolt is a common standard part. The existing T-shaped track bolts, especially those used in high-speed railways, are often installed in pre-buried tracks, and the T-shaped track bolts are not easy to install, which may easily cause positional deviation.
Use performance self-tapping screws for self-tapping screws with a diameter of 0.8mm to 12mm. For this type of screw, it generally has a high hardness. Self-tapping screws must be screwed into the test, that is, screw the screw into a test plate to check whether the hardness of the screw meets the standard. The shape of the drill tail, the hardness of this kind of screw is very strong. Compared with ordinary screws, it not only has better maintenance ability, but also has a very strong effect in connecting objects. For screws with this performance, it is generally not necessary. Auxiliary processing can directly drill a hole on the object and lock it into the object, which is not only very convenient to use, but also greatly improves work efficiency. This kind of drill screw can be said to be the first choice of the staff in various fields.
The existing automobile fastener nut is a common nut. After the nut is matched with the bolt, during the tightening or disassembly process, there will be a phenomenon of sliding wire, and the safety factor is relatively low; It is difficult to guarantee, easy to rust, requires frequent inspection and replacement, and increases the cost of using the car, which can no longer meet the needs of the market.
When the countersunk head screws and hexagon socket head bolts are produced by the cold heading process, the original structure of the steel will directly affect the forming ability of the cold heading process. In the process of cold heading, the plastic deformation of the local area can reach 60%-80%, so the steel must have good plasticity. When the chemical composition of the steel is constant, the metallographic structure is the key factor to determine the plasticity. It is generally believed that the coarse flaky pearlite is not conducive to cold heading forming, while the fine spherical pearlite can significantly improve the plastic deformation ability of the steel. For medium carbon steel and medium carbon alloy steel with a large amount of high-strength bolts, spheroidizing (softening) annealing is performed before cold heading, so as to obtain uniform and fine spheroidized pearlite to better meet the actual production needs. For the softening annealing of medium carbon steel wire rods, the heating temperature should be kept above and below the critical point of the steel, and the heating temperature should not be too high, otherwise tertiary cementite will precipitate along the grain boundary, resulting in cold heading cracking. The wire rod of medium carbon alloy steel is annealed by isothermal spheroidization. After heating at AC1+ (20-30%), the furnace is cooled to slightly lower than Ar1, the temperature is about 700 degrees Celsius for an isothermal period, and then the furnace is cooled to about 500 degrees Celsius and air-cooled. The metallographic structure of the steel changes from coarse to fine, from flake to spherical, and the cracking rate of cold heading will be greatly reduced. The general area of softening annealing temperature for 35\45\ML35\SWRCH35K steel is 715-735 degrees Celsius; while the general heating temperature for spheroidizing annealing of SCM435\40Cr\SCR435 steel is 740-770 degrees Celsius, and the isothermal temperature is 680-700 degrees Celsius.
structure for concealing installation screws, comprising a locking piece, a driving piece, a bottom plate, a blocking cover and a handle head, the lower ends of the two locking pieces are provided with positioning holes, and the locking pieces pass through the positioning holes and the locking piece positioning posts on the base The occlusal and fixed, the middle of the two locking pieces is provided with a protruding point, the movable groove of the driving piece corresponds to the protruding points of the three locking pieces for fixing, the riveting point holes and screw holes of the bottom plate and the riveting points of the base The position that matches the screw holes and is fixed by screws, the blocking cover is directly inserted into the bottom plate, and the blocking cover is fixed by the rotating drive piece, the handle head is inserted into the base, and the slot of the handle head moves to the locking piece at the locking piece Lock the handle.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: casing gaskets, 70 manganese Dacromet washers, GB91 stainless steel, external tooth stop gaskets and other products, we can provide you with suitable products for you fastener solutions.
