STRUCTURAL MEMBER FOR AUTOMOBILE

The present invention aims to improve flexural strength of car structural members, such as bumper reinforcements, having an M-shaped cross section. In a car structural member of the present invention, the outer walls (42) of the two ridges (32, 34) have steps (44) and therefore have increased rigidity, while inner walls (40) of the ridges (32, 34) are flat and therefore have a lower rigidity. This restrains widening deformation of the outer walls (42) when impact forces are applied from the side into which the ridges (32, 34) project in the event of a vehicle collision. The outer walls (42) are deflected without being widened under a larger load. The car structural member thus has an improved flexural strength.