Abstract: To enable welding in a state in which aluminum plating in a desired welding region is removed at a desired high accuracy, a plating layer (103) in a welding region (151) and a plating layer (104) in a welding region (152) are removed using an alkaline solution to form a preprocessed aluminum plated steel sheet (101a), and a plating layer (123) in a welding region (153) and a plating layer (124) in a welding region (154) are removed using an alkaline solution to form a preprocessed aluminum plated steel sheet (121a).

Abstract: An aluminum plate (103) is overlaid on a steel plate (102). A distal end (113) of a button component (101) is pushed in from the obverse surface side of the aluminum plate (103), and the distal end (113) is abutted against the steel plate (102) by applying a first pressure to the button component (101) made of steel without heating. The distal end (113) of the button component (101) and the steel plate (102) are welded by resistance spot welding while applying a second pressure lower than the first pressure to the button component (101).

Abstract: An oil hole penetrating through a partition wall of a pulley cover of a continuously variable transmission is formed in a direction perpendicular to an axis of the pulley cover. The pulley cover, having first and second hydraulic oil chambers through which a movable pulley half of a pulley of the continuously variable transmission is biased toward a fixed pulley half thereof, is manufactured in the step of machining a metal sheet. The manufacturing step includes a first step of press-forming the annular partition wall of the pulley cover, a second step of opening the oil hole in the partition wall, the oil hole allowing communication between the first and second hydraulic oil chambers, and a third step of press-forming the peripheral wall of the second hydraulic oil chamber at an outer side, in a radial direction, of the partition wall.