The part that is placed between the connected part and the nut. Generally, it is a flat metal ring used to protect the surface of the connected part from being scratched by the nut, and to disperse the pressure of the nut on the connected part.
Washers are divided into: Flat Washers - Class C, Large Washers - Class A and C, Extra Large Washers - Class C, Small Washers - Class A, Flat Washers - Class A, Flat Washers - Chamfer Type - Class A, High Strength Washers for Steel Structures, Spherical Washers, Conical Washers, Square Diagonal Washers for I-beams, Square Diagonal Washers for Channel Steel, Standard Spring Washers, Light Spring Washers, Heavy Spring Washers, Inner Toothed Lock Washers, Inner Toothed Lock Washers, Outer Toothed Lock Washers, Outer Toothed Lock Washers, Single Ear Stop Washers, Double Ear Stop Washers, Outer Tongue Stop Washers, and Round Nut Stop Washers.
Flat washers are generally used in connectors, one is soft and the other is hard and brittle. Their main function is to increase the contact area, disperse pressure, and prevent the soft material from being crushed. The basic function of the spring washer is to apply force to the nut after tightening it, increasing the friction between the nut and the bolt! The material is 65Mn (spring steel), with a heat treatment hardness of HRC44-51HRC, and has undergone surface oxidation treatment.
Huasi (spring) washer, snap spring is an elastic cushion or snap lock washer that prevents bolts from loosening. The working principle of the anti loosening washer is very simple. It consists of two washers. The outer side has a radial convex surface, while the inner side has a helical tooth surface. When assembling, the inner inclined tooth surfaces are relative to each other, and the outer radial convex surface is in an interlocking state with the contact surfaces at both ends. When the connecting piece is subjected to vibration and causes the bolt to loosen, only the relative displacement between the inner inclined tooth surfaces of the two washers is allowed, generating lifting tension and achieving 100% locking.
Spring washers are widely used in load-bearing and non load-bearing structures of general mechanical products, characterized by low cost, easy installation, and suitability for frequently disassembled parts. The automatic selection of washers is included, but the anti loosening ability of spring washers is very low! Especially in products with high reliability requirements in European and American countries, the adoption rate is extremely low, especially in important load-bearing structural connection parts that have long been abandoned. Our country still has some applications in the military industry, but they have been improved to stainless steel materials. Steel spring washers have long been banned from use in CASC! It can also be said that it is very unsafe, for two reasons: 1) "swelling circle" and 2) hydrogen embrittlement.
Spring washers are commonly referred to as spring washers in the screw industry. Its materials include stainless steel and carbon steel, and carbon steel is also known as iron. The commonly used spring washer specifications include M3, M4, M5, M6, M8, M10M12, M14, M16. These specifications are quite common. The national standard GB/T 94.1-87 for spring washers specifies standard spring washers with a size of 2-48mm. Reference standard GB94.4-85 "Technical Conditions for Elastic Washers - Spring Washers"
1. The C-grade gasket does not have the requirements for Ra3.2 and deburring.
2. C-level is suitable for medium assembly series, and A-level is suitable for fine assembly series
3.G B848-85 is mainly used for cylindrical head screws, while others are used for standard hexagonal bolts, screws, and nuts
Material mechanical performance level: Steel 200HV; Austenitic stainless steel A200
Marking example: Standard series, nominal size d=8mm, performance grade 200HV, plain washer without surface treatment: washer GB97.1-85 8 200HV
Material selection
The materials of rubber gaskets usually include NBR (nitrile rubber), SBR (styrene butadiene rubber), HNBR (hydrogenated butadiene acrylic rubber), EPDM (ethylene propylene diene monomer rubber), SILICONE (silicone), VITON (fluorine rubber), CR (chloroprene rubber), FFKM (perfluorinated rubber), etc. The material selection of rubber gaskets is most commonly used with NBR nitrile rubber, which has the highest cost-effectiveness. The use of FFKM perfluorinated rubber gaskets is generally in more cutting-edge fields, such as aerospace rockets. Because its price is quite expensive, but its performance is excellent and can surpass many metal materials
Combination washer
It is a sealing ring made by bonding and vulcanizing rubber and metal rings as a whole, used to seal threaded and flange connections. The ring includes a metal ring and a rubber sealing gasket. Metal rings are treated with rust prevention, and rubber rings are generally made of oil resistant nitrile rubber or fluororubber. Combination pads come in two sizes, metric and imperial, with a combination of metal pads and rubber as specified in standard JB982-77. Combination sealing gaskets are used for sealing threaded pipe joints and screw plugs. They are generally used together with sleeve type pipe joints to block oil ports. They are mainly used for static sealing of the end face at the threaded connection of hydraulic valve pipe joints, and are suitable for static sealing of the end face at the connection of British and American standard British threads and French and German standard metric threads. Combination sealing gaskets can be divided into Type A and Type B according to their structural form; According to the different types of adhesive, it can be divided into full package and half package.
