Flat Washers
The principle of a flat washer is to increase the contact surface area of the connected parts, reduce the pressure per unit area and protect the surface of the connected parts from damage. It mainly has the functions of reducing pressure, increasing friction, sealing, damping, and fixing.
For example, there are hundreds or thousands of different types of fasteners used in a car, and flat washer combination screws are widely used in vehicle fasteners. Nowadays, the requirement for vehicles lightweight is getting higher. A lot of lightweight connection technologies and structures are used in body and even chassis structure parts. In order to reduce the compressive stress of the bearing surface of the connecting piece in the bolted joint and to prevent crushing and permanent plastic deformation, it is generally necessary to add flat washers.
In some applications, such as automobiles, stamping and welding parts are mostly used, and the positioning of the holes between the two parts is not a good match. To ensure that the bolt holes match one another between the two connections, we need to increase the hole diameter to compensate for the hole position deviation. When the bolt holes exceed the standard requirements, the compressive stress exceeds the strength of the material. In this case, the flat washer needs to be increased.
Flat washers are generally the most commonly used size using the internationally recognized DIN125 standard.
Spring washer
Spring washer is mainly to increase friction between nut and bolt, that is, to prevent the running equipment from loosening fastening bolt due to vibration. The added protective measures have anti-seismic and anti-loosening effects.
For example, spring washers are usually added to the bolts connecting the motor to the base because the motor vibrates and the nuts will loosen if there is no spring washer. Spring washers are usually fitted to fasteners on equipment with vibration.
Another example is commonly used furniture tables, where the legs are fixed and bolts and nuts are connected using spring gaskets. Because once there is a gap between the bolts and nuts, the furniture will inevitably shake over a long period of time, possibly loosening the screws. And the wood will expand and shrink. The main function of the spring washer is to give buffer space. After being compressed, it will rebound. The most commonly used size of the spring washer is also according to the internationally recognized DIN 127 standard.
