The defective phenomena of dimensional accuracy, cracking, and wrinkling, etc. are generated in the flanging process of press forming such as the panel parts of car body. In this study, the experimental model forming and the analysis are done to clarify the characteristics of shearing deformation, which causes a defective phenomenon of dimensional accuracy of flange height in stretch-type, shrink-type and reverse-type flanging of sheet metals. There is a close relationship between the amount of shearing deformation and the profile curvature (1/R) of flange. An analytical modeling of shearing deformation of flange has been led, and the amount of shearing strain can be calculated by introducing the equivalent curvature(1/ρ0).
