style="text-align: justify;">style="text-align: justify;">The metal push button switch is a switch that pushes the transmission mechanism with a button to make the movable contact and the static contact open or close and realize circuit switching. The button switch can be divided into a normally open button, a normally closed button, a composite button, and the like. The push button switch can perform basic control such as start, stop, forward and reverse, shifting and interlocking. Usually, each push button switch has two pairs of contacts, each pair consisting of a normally open contact and a normally closed contact. When the button is pressed, the two pairs of contacts act simultaneously, the two pairs of normally closed contacts are first disconnected, and then the two pairs are normally open and closed. There are many types of button switches, which can be divided into ordinary button type, mushroom head type, self-locking type, self-resetting type, rotary handle type, with indicator light type, illuminated symbol type and key type, etc. Buttons, three buttons and different combinations are generally made up of modular structures, consisting of button caps, return springs, bridge contacts and housings. They are usually made into a composite type with a pair of normally closed contacts and normally open contacts. Some products can increase the number of contact pairs by connecting multiple components in series.