Service HotlineThe 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%.
The flat washer is mainly used to reduce the pressure. When some parts are tightened with a large axial force, it is easy to press the washer into a dish shape. At this time, it can be solved by changing the material and increasing the hardness.
As one of the indispensable parts in automobiles, the main function of the screw is to fix the parts with through holes and the parts with screw holes together. The existing automobile screws include a screw rod and a head, and the thread pitches on the screw rod are equal. , When in use, directly screw the screw into the screw hole, so as to connect and fix the two parts, this connection method, however, when the screw has different thread spacing or part of the thread is damaged, the thread cannot be repaired and replaced. Then the whole screw will be scrapped.
The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to overcome the above shortcomings and provide a limit screw. The technical scheme of Guangdong Yueluo Hardware Industry Co., Ltd. is realized in the following way. Its structure is composed of screws, hexagonal copper posts and limit necks. The left end of the limit neck is open, the hexagonal copper column is communicated with the inside of the limit neck, and the inside is provided with screw threads. The design length of the screw thread in the hexagonal copper column is 1/3-2/3 of its own length. The advantages of Guangdong Yueluo Hardware Industry Co., Ltd. are (10), which can effectively prevent the problem of poor memory contact caused by the increase of the deformation of the motherboard due to the warping and deformation of the motherboard during installation and fixation, and can effectively control the deformation. effect.
Locking of screws belongs to the prior art. Or by means of a visual method (X-ray control) a more or less complex aiming device is inserted into the transverse hole of the screw. In both cases a certain misalignment is unavoidable, ie the screw may not be coaxial with the central axis of the transverse hole and deviate from it by a certain value. In order for the locking screw to pass into and through the transverse hole despite this misalignment, the outer diameter of the screw is determined to be a size smaller than the diameter of the transverse hole. If the aiming is not maintained within this small dimension value, the locking screw can pass through the transverse hole without difficulty despite the aiming error. Now, however, the locking screw has a certain clearance relative to the transverse hole due to the determination of a smaller size value.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: combination flat head bolts, round head inner bolts, small hexagon screws, red steel paper washers and other products, we can provide you with suitable fasteners for you solution.
