Automobile bumpers formed from rolled sheet steel and each having a cross-sectional profile designed to carry impact loads without additional reinforcements, and which are selectively hardened to withstand impact of a high order of magnitude without damage. At least an area of the bar coextensive along the bar remains unhardened and serves to control and avoid distortion of the hardened areas. In a relatively large shell bumper profile, longitudinal areas near the neutral axis of the profile remain unhardened and there are longitudinal hardened areas at the profile portions farthest from the neutral axis.P P A method of and means for effecting selective hardening of the bumper face bars are also disclosed.
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