The screws with rubber pads are big enough. Do you know the function of plastic flat pads?

There are thousands of screws, such a kind of screws, always with a pad, rubber pad and so on. Why is it easy to see the use of plastic mats on electronic and digital products? The purpose is to prevent electric conduction, light weight and so on. But in the mechanical industry, plastic fasteners, such as those mentioned above, are also widely used.
Ingenuity, fastener, sunk head, self drilling pin, drilling screw, machine and so on are all popular with many customers. The screws with rubber pads are not only scratched, but also electrically conductive. There are many important roles. Such as:
Undefined
1, sealing action, waterproof, leak proof. In practical applications, prevent water, oil and other liquids from slipping along threads.
2, prevent scratch 0, prevent scratches, such as the surface of the device, heat treatment paint layer.
3, anti loosening action. The cushion can also increase the stress area and play a role of tightening up and strengthening.