Types of Washers for Bolts,Flat Washer vs Spring Washer

Washers are bearing and non-bearing structures that are widely used in general mechanical products. They are characterized by low cost, easy installation, and are suitable for parts that are frequently loaded and unloaded. In particular, the adoption rate of high-reliability products in European and American countries is extremely low, especially the important load-bearing structural connecting components that have been abandoned for many years. The material of the washer is stainless steel and carbon steel, carbon steel is iron.

Types of Washers

In order to reduce costs when connecting workpieces, many users want to save flat washers or spring washers. In fact, flat washers and spring washers play an indispensable role in the use of bolts.

DIN125 Stainless Steel Flat Washers

DIN125 Stainless Steel Flat Washers

Flat washers are mainly stamped with iron plates, generally in the shape of flat washers with holes in the middle.

Flat washers are usually thin pieces of various shapes used to reduce friction, prevent leakage, isolate, and prevent loosening or disperse pressure. Many materials and structures have such components to perform a variety of similar effects.

DN127 Stainless Steel Spring Washers

DN127 Stainless Steel Spring Washers

Due to the material and process limitations of threaded fasteners, the supporting surface of bolts and other fasteners is not large. Therefore, in order to reduce the compressive stress of the pressure bearing surface and protect the surface of the connected parts, the spring washers are placed between the connecting parts and the connected parts between the nuts and bolts.

In order to prevent the loosening of the connector, the anti-loosening spring washer and multi-tooth lock washer types, round nut stop washer and saddle spring washer, wave spring washer, and conical spring washer are used.

DIN137A Saddle Type Spring Washers

DIN137A Saddle Type Spring Washers

Flat washers are mainly used to reduce pressure. It is easy to press the gasket into a disk when the axial force in some parts is high. At this point, materials and hardness can be used to solve.

The following summarizes the role of the flat washer:

  1. Increase the contact area between the screw and the machine.
  2. Eliminates damage to machine surfaces by spring washers during screw removal. When using, it must be a spring washer and a flat washer, the flat washer is close to the surface of the machine, and the spring washer is between the flat washer and the nut.

DIN137B Wave Type Spring Washers

DIN137B Wave Type Spring Washers

The Difference Between Flat Washer and Spring Washer

Spring Washer Anti-Loosening Principle

The anti-loosening principle of the spring washer is that after the spring washer is flattened, the spring washer will generate continuous elasticity, so that the threaded connection pair of the nut maintains the friction force, generating a resistance torque, and prevents the nut from loosening. At the same time, the sharp corners at the opening of the spring washer are embedded in the surfaces of the bolt and the joint respectively, preventing the bolt and joint from rotating.

The Washer Material

Generally, 65MN spring steel or 70# carbon steel, 3Cr13, stainless steel SUS304, or SUS316 can also be used. Or other low-carbon steel, such as Q235, Q195, etc.

Carbon Steel Blackened Spring Washer

Carbon Steel Blackened Spring Washer

The Role of Flat Washers

  1. Increase the contact area between screw and machine.
  2. Eliminate damage to machine surfaces by spring washers when removing screws. Must be: spring washer – flat washer, flat washer close to machine surface, spring washer between flat washer and nut. Flat washers are used to increase the stress surface of the screw. In order to prevent the screw from loosening, the spring pad plays a certain buffering protection role when it is stressed.
  3. But flat washers are usually used as supplementary washers or flat pads.

The Role of Spring Washers

  1. The function of the spring washer is that after the nut is tightened, the spring washer gives the nut an elasticity, and the nut is tightened so that it is not easy to fall off. The basic function of the spring is to apply a force to the nut after tightening it, increasing the friction between the nut and the bolt.
  2. Flat washers are generally used in connectors, one is soft and the other is hard and brittle. Its main function is to increase the contact area, disperse the pressure, and prevent the soft material from being crushed.

When to Use A Flat Washer and When to Use A Spring Washer?

In general, when the load is relatively small and does not bear the vibration load, only flat washers can be used.

When the load is large and it is subjected to vibration load, a combination of flat washer and spring washer must be used.

Spring washers are basically not used alone but in combination.

The above is a brief introduction to the function of the flat pad. It can be seen that flat washers and spring washers are very important in machine connection, which can make the machine used in a safer environment, and are indispensable small parts.

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