According to the different flanging direction, it can be divided into vertical flanging, horizontal flanging and inclined flanging. Among them, the vertical flanging, the trimming piece opens up, the forming is stable, the positioning is convenient, and the air pressure cushion can also be used to press the material, when conditions permit The following should be used as much as possible. In addition, according to the number of flanging surfaces, it can be divided into single-sided flanging, multi-sided flanging, and closed curve flanging. According to the deformation properties of the blank in the flanging process, it can be divided into elongated screen curve flanging, elongated curved surface flanging, compression flat curve flanging and compression curved surface flanging.