Abstract: A method and inductor are provided for annealing the corners of an elongate hollow structural beam in which the corners become work hardened when the beam is produced by cold working initially flat metal plate to the hollow beam configuration. The corners of the beam are inductively heated progressively along the length of the beam in a manner which concentrates heat in the corners and controls the spreading of heat into the sides of the beam from the corners so that the work hardened areas are annealed to provide for the corners and walls to be more uniform in hardness and strength in connection with use of the beam as a structural member.

Abstract: A method and inductor are provided for annealing the corners of an elongate hollow structural beam in which the corners become work hardened when the beam is produced by cold working initially flat metal plate to the hollow beam configuration. The corners of the beam are inductively heated progressively along the length of the beam in a manner which concentrates heat in the corners and controls the spreading of heat into the sides of the beam from the corners so that the work hardened areas are annealed to provide for the corners and walls to be more uniform in hardness and strength in connection with use of the beam as a structural member.

Abstract: An inductor coil is provided for inductively heating a hollow automotive front wheel spindle which has axially extending outer surface areas of different radial thickness. The coil has a single loop between the terminal ends thereof defined by circumferentially extending arcuate inductor portions which are axially spaced apart and connected with one another by means of axially extending inductor portions. The arcuate inductor portions are circumferentially progressive with respect to one another in the direction from one of the terminal ends of the inductor toward the other, and each arcuate portion is associated with a different one of the axially extending surface portions of the workpiece. Each arcuate portion has a circumferential extent different from the other two.