Service HotlineThe technical problem to be solved by Guangdong Yueluo Hardware Industry Co., Ltd. is to overcome the deficiencies of the existing rivets. The purpose of this utility model is to provide a special rivet for railway freight cars, which can be reused and increase the safety factor. , to limit the movement of the collar in the circumferential direction.
Round head three-combination screws are also called pan-head three-combination screws, which are divided into large pan-head three-combination screws and small pan-head three-combination screws. The materials are divided into stainless steel and iron. The stainless steel round head three-combination screws include stainless steel small pan head three-combination screws and stainless steel large pan-head three-combination screws. The national standards are respectively expressed as GB9074.8 and GB9074.4.
Fasteners are a type of mechanical parts that are used for fastening connections and are widely used. Fasteners are used in a wide range of industries, including energy, electronics, electrical appliances, machinery, chemicals, metallurgy, molds, hydraulics, etc., in various machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, etc. , chemical industry, instruments and supplies, etc., all kinds of fasteners can be seen, which are the most widely used mechanical basic parts. It is characterized by a wide variety of specifications, different performance uses, and a very high degree of standardization, serialization and generalization. Therefore, some people also refer to a type of fasteners with existing national standards as standard fasteners, or simply as standard parts.
High-strength fastener materials mainly include ML35, 35K, ML40Cr, ML35CrMo steel, etc., of which 75ML35CrMo steel is imported. The main problems of the material are box segregation, decarburization, cracks and so on. The material needs to be spheroidized and annealed before cold forming, and the annealing is carried out in an oil furnace. There is no protective atmosphere in the furnace, and there is a decarburization phenomenon. 1.2 The high-strength fasteners, mainly grade 12.9, are quenched and tempered on the chain casting furnace production line. The temperature and atmosphere in the furnace are controlled by computer, and Rx gas is used as a protective atmosphere. Heating and anti-oxidation and decarburization can be effectively controlled, and the quality of the fasteners is intact during the heating process. The high-strength fasteners mainly of grade 8.8 are quenched and tempered on the vibrating hearth furnace. Affected by the structure of the vibrating hearth furnace, the sealing performance of the furnace is poor, the Rx atmosphere is not easy to control, the temperature difference of the furnace is large, and the parts are heated in the furnace. The collision and the length of time are inconsistent, and the quality of the fasteners during the heating process is poor, and there are phenomena such as decarburization, bumps, and uneven heating.
4. Manufacturing and assembly Due to the limitations of manufacturing technology and accuracy, there are sharp corners on the edge of the thread or the dimensional coordination between parts is not coordinated. During the initial assembly, the screw-in and screw-out torque may fluctuate or fluctuate to a certain extent. After a certain number of running-in, more accurate reusability characteristics of the lock nut can be obtained.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: retaining ring gaskets, column plastic spacers, hexagonal nut columns, carbon steel K-cap nuts and other products, we can provide you with suitable tightening. Firmware Solutions.
