A method of forming honeycomb panels of high strength material whereby the panel to be formed is positioned between an inner metallic cover sheet and an outer sheet of resilient material. The sandwich pack so formed is disposed between die set members which are moved relative to each other to deform the pack. During the forming operation, the edge portions of individual honeycomb cores bite into the bonding surface of the resilient cover sheet material which functions as a structural restraint to minimize dimensional failure by preventing the spreading apart of adjacent cores one from another on the tension side of the bend. All of the bending of the panel is taken in uniform deformation on the compression side of the panel.