A skid plate comprising a core material (11) having a rectangular or trapezoidal corrugating medium material (13) extending in a lengthwise direction, and flat plates (14, 15) bonded to upper and lower surfaces of the corrugating medium material (13). While the skid plate is equivalent to a prior art one in out-of-plane flexural rigidity in the lengthwise direction, it is small in a ratio of torsional rigidity to out-of-plane flexural rigidity and is large in out-of-plane flexural rigidity in a widthwise direction.
