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Wholesale 10.9 grade black high strength flat head bolts black hardened hexagon socket head countersunk head screws 3/4

author:[email protected] Click:5499end source: time:2024-01-01 11:20:09

Summary of information:We have more than ten years of production experience in the screw industry. The main products are: plastic support colum...

The 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.

The flat gasket product is an accessory on the high-speed rail backing plate. The product requires two planes to be flat, the shape and size of the inner hole are accurate, and there are no casting defects (such as air holes, shrinkage holes, sand holes, etc.), and the casting material requires GB/T450-10 . Due to the light weight and large demand of flat gaskets, if they are produced by ordinary sand casting process, the castings are prone to deformation, sand holes, air holes and other casting defects, and the molding area is large, the production efficiency is low, and the production tasks are difficult to complete.

High-strength self-locking nuts are a category of self-locking nuts with high strength and reliability. It is mainly based on the introduction of European technology, which is used for road construction machinery, mining machinery, vibration machinery and equipment, etc. There are very few domestic manufacturers of such products.

At present, the convex washers with traditional structures on the market have unreasonable designs and complex structures, and are inconvenient to install and disassemble. After long-term use, they are prone to fracture and deformation due to poor toughness, resulting in short service life and requiring regular downtime for maintenance, affecting assembly. The working efficiency and safety of its equipment are also poor in terms of wear resistance, corrosion resistance, and high temperature resistance. Regular replacement and maintenance also increase the economic cost of production. Therefore, the convex gasket of the existing structure can no longer meet the existing mechanical requirements. The high standard use requirements of assembly auxiliary parts are urgently needed to be solved at present.

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.

We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: black hexagon socket head screws, torx flat head screws, countersunk head flat head screws, hexagonal copper column isolation column nuts and other products, we can provide you with suitable products Your fastener solution.

blackened high strength

Wholesale Level 10.9


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