There are many types of pliers, and they have a wide range of uses. They are indispensable hand tools for gripping and shearing workpieces in various industries, such as assembly, repair, and installation. But it has a common basic structure, which is that any hand pliers county is composed of three parts: Pliers head, pin, and pliers handle. The basic principle of pliers is to use two levers to cross connect with pins at a point in the middle, so that the two ends can move relative to each other. As long as the tail end is operated by hand, the other end can clamp the object. In order to reduce the force required by the user during operation, according to the principle of leverage in mechanics, the handle of the pliers is usually made longer than the head of the pliers, which can achieve stronger clamping force with less force and meet the requirements of use. [1]