4-point crimping method. 4-point crimping (square crimping or quadrilateral double crimping) is generally suitable for wires under 6 square meters. When the wire and the terminal are well matched, the terminal profile and pull-off force are also qualified after crimping. The number of squares of wires commonly used in 4-point crimping is 3 squares, 4 squares, and 6 squares, of which 3 square wires and 4 square wires are more. During the crimping process, it is necessary to insert the wire into the terminal crimping hole first, and then hold the wire and the terminal for crimping. During the crimping process, it is necessary to prevent the terminal from falling off, which will affect the operation efficiency.