<p>This study investigates the deformation and contact characteristics of sheet metal bending with rotatable dies through finite element analysis and bending experiments. By comparing the process with conventional V-bending, the advantages of bending with rotatable dies were analyzed. The effects of key die design parameters, including the rotatable die diameter, punch radius, and die-center distance, were examined to identify the governing geometric factors in the process. The results showed that the distance from the center of the die assembly to the center of rotation of the rotatable die, denoted as δ, rather than the rotatable die diameter itself, primarily governed the deformation characteristics. When δ was fixed, similar load–stroke responses and strain distributions were obtained even with different rotatable die diameters. To further clarify the contact behavior, the contact pressure distribution on the rotatable die was analyzed using a deformable-die model, and the effective inner and outer contact lengths, R_in and R_out, were evaluated. The contact lengths increased almost linearly with sheet thickness, providing a basis for determining the required die radius. Based on these contact characteristics and simplified geometric assumptions, a minimum value of δ was derived to prevent undesirable thickness-direction deformation. These findings provide design-oriented criteria for selecting the key process parameters in sheet metal bending with rotatable dies.</p>