The lifting ring screws are generally not surface treated, but according to the requirements, surface treatment such as galvanized passivation and chrome plating can be carried out, and it is specified in GB5267-85. The chemical composition and mechanical properties of the material should be treated immediately after electro-galvanizing. The test methods are specified in GB699. During routine inspection, the grain size test may not be advanced, and the grain size test method shall be in accordance with the provisions of YB27. Thread inspection is performed with thread gauges and smooth limit gauges or universal energy tools.
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 (7), 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 amount of deformation effect.
The front wall sound insulation pad is used to absorb the heat and noise transmitted by the firewall, and also plays the role of heat insulation and vibration isolation, ensuring a relatively quiet and comfortable environment in the car and improving ride comfort. As shown in FIGS. 1 and 2 , the front wall sound insulation and heat insulation pad 101 is generally fixed to the vehicle body by means of screw buckles 102 . The screws 100 are clamped by the clamping feet 103 in the screw The limiting rib 104 clamps the screw 100. After the screw 100 is clamped into the screw buckle 102, the tail end of the screw 100 is exposed, which is easy to scratch the operator when assembling other components, and the exposed screw 100 is easy to cause corrosion, thereby affecting the connection strength of the screw 100, and also The service life of the screw 101 is reduced.
In the prior art, the spring washer has a certain anti-loosening effect. However, due to the unreasonable design structure, the upper and lower pressing forces of the spring washer and the spring washer's anti-return force are poorly matched, resulting in the smooth surface and the bolt head. The friction between the nut and the connected parts is small. When the bolt or nut is subjected to strong vibration, the bolt or nut will still loosen. Therefore, the anti-loosening effect of the above spring washer still needs to be improved.
The self-tapping locking screw is a series of coarse thread and ordinary thread, and the thread size is M3~M12mm. The threaded rod of the self-tapping locking screw is a thread with an arc-shaped triangular section. The screw is surface hardened and can be screwed into a prefabricated hole of black or non-ferrous metal material (which can be made by drilling, punching or die casting), and extruded to form an internal thread. The threaded rod portion can be made into a cylindrical or triangular shape with a diameter equal to or less than the circumscribed circle. Self-tapping locking screws have low screw-in torque and high locking performance. The varieties of self-tapping locking screws in the product standard of Chinese commodity fasteners include GB/T6560 (cross-recessed pan head), GB/T6561 (cross-recessed countersunk head), GB/T6562 (cross-recessed half-sunk head), GB/T6563 ( Hexagon head), GB/T6564 (hexagonal flower-shaped cylindrical head) five series. Self-tapping locking screws are generally fastened with pneumatic or electric screwdrivers. Most of the automotive industry uses hexagonal head, cross recessed pan head and hexagonal socket head self-tapping locking screw with high fastening efficiency.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: full threaded screws, B18.2.2 hexagon nuts, 12.9 hexagon socket screws, hexagon socket screws and other products, we can provide you with suitable tightening bolts. Firmware Solutions.