Processes for reducing the number of stages and adjusting wheel sizes in one-piece press forming of automobile steel wheels without welding were proposed. The number of stages was considerably reduced from 16 stages to only 9 stages by combining the deep drawing and ironing stages and by adding a holding die in the flaring stages. The width of the rim was adjusted by the length of punches in the redrawing stages, and the offset of the attachment of the disk to the rim was adjusted by the punch stroke in the disk finishing. In addition, the humps of the rim flange for fixing the tire were formed in the flaring and flanging stages. The proposed forming sequence of the one-piece wheels was evaluated by both finite element simulation and miniature experiment.