Service HotlineOrdinary snap-type retaining rings have ears on their structure, which cause interference with the inner parts. If the ears are not provided, it is very troublesome to disassemble. For the very demanding aerospace field, ordinary snap rings cannot meet their requirements.
Commonly used screw materials in my country are No. 45 steel, 40Cr, ammoniated steel, 38CrMOAl, superalloy, etc. 1) No. 45 steel is cheap and has good processing performance, but poor wear resistance and corrosion resistance. Heat treatment: quenched and tempered HB220-270, high-frequency quenched HRC45--48. 2) The performance of 40Cr is better than that of No. 45 steel, but it is often plated with a layer of chromium to improve its corrosion resistance and wear resistance. However, the requirements for the chrome plating layer are relatively high. If the plating layer is too thin, it is easy to wear, and if it is too thick, it is easy to peel off. After peeling off, it will accelerate the corrosion, and it has been rarely used. Heat treatment: quenched and tempered HB220—270, hard chrome plated HRC>553) nitrided steel, 38CrMoAl have excellent comprehensive properties and are widely used. Generally, the nitride layer reaches 0.4-0.6 mm. However, this material has low resistance to hydrogen chloride corrosion and is relatively expensive. 4) The superalloy material is superior to other materials. This material does not need coating, and is mainly used for the raw halogen-free screw of injection molding machine. The material has high oxidation resistance and corrosion resistance.
Cabinets are one of the must-have furniture in home improvement homes. They are extremely useful. Various cabinets may be used in kitchens, bathrooms, bedrooms, living rooms, and even balconies. The traditional cabinets are assembled in advance and then placed in the appropriate position, which is very inconvenient to transport. Currently, the commonly used cabinets are spliced together with plates and hardware accessories. During production and transportation, the plates and hardware accessories are independent. For production, processing and transportation, after it is sent to the destination, it is assembled with the plates by screws and other hardware accessories to form the entire cabinet structure. The current cabinet installation structure usually exposes some hardware accessories such as screws on the outside or inside of the cabinet, which not only affects the overall aesthetics, but also scratches the items during use, which affects the use effect. Some designs allow a plastic fastener to be fastened on the outside of hardware accessories (mainly screws). Although it can alleviate the above problems to a certain extent, it still does not fundamentally solve the problem, and the integrity is still not good.
Subway tunnels can be divided into rectangular, arched, circular, and elliptical end face forms according to the section shape of the section tunnel. The rectangular end face can be divided into single-span, double-span and multi-span types. There are two types of circles. The subway tunnel needs to install electromechanical equipment through bolts, insert T-shaped bolts into the preset holes on the shield plate of the subway tunnel, and then cast and fix it. The bolts are smooth and the contact surface is small. The bolts installed in the shield plate are easy to fall off, causing the installed equipment to fall and damage or causing losses to pedestrians or vehicles passing in the tunnel. Therefore, it is necessary to further improve the current bolts.
The national standard for the size of the screws in the round head three-combination screw is GB818. The main technical requirements of various types are: iron and stainless steel for material requirements, low, medium and high carbon steel for iron, and stainless steel combination screws The materials are stainless steel 201, stainless steel 304 and stainless steel 316. The thread tolerance is 6G, and the mechanical properties of the iron combination screws are 4.8 and 8.8. The 4.8-level combination screws are ordinary steel, and the maximum allowable hardness is 255HV. The 8.8-level combination screws are generally made of wire rod 10B21. , and then undergo hardening treatment, and then dehydrogenation after hardening treatment. Hydrogen removal is to prevent hydrogen embrittlement of the spring washer in the combination screw. Prevent the spring pad from breaking. The tolerance class of the combination screws is A. The cross groove is H-shaped. The surface treatment of the combination screw has environmental protection and non-environmental protection. Such as, environmental protection blue zinc, environmental protection color zinc, black zinc, color zinc, white nickel and so on. The technical requirement of the combination screw for the spring washer is that the washer should be able to rotate automatically without falling off.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: carbon steel bolts, national standard explosion screws, special nuts, metal flat washers and other products, we can provide you with suitable fastener solutions for you.
