Providing a bumper absorbing large amount of impact energy with respect to both a light collision and a heavy collision, and preventing the reinforcement beam from bending and protruding backward at a portion where an obstacle collides and from displacing backward in this protruding state. Provided is a bumper for vehicles including a reinforcement beam made of metal and a pair of support members having a hollow cross section, protruding from a vehicle frame, and supporting the reinforcement beam therebetween. A quenched region is provide over a portion including a middle of the reinforcement beam. Unquenched portions are provided on the pair of connecting portions or a pair of adjacent portions inside the pair of connecting portions.