WASHING MACHINING AND MANUFACTURE THEREOF

PROBLEM TO BE SOLVED: To enable a rotary body and a boss to be firmly combined by forming a circular fitting part at about the central part of the rotary body main body and fixing a boss in a polygonal shape therein by drawing work, etc., in a rotary body such as a pulley, etc., equipped with the main body comprising a metal plate and a thick metal boss. SOLUTION: A rotary body such as a pulley to transmit motor power of a washing machine has a rotary body main body equipped with a belt groove 4 on the outer periphery and is formed of a metal sheet, and a boss 2 made of a thick metal plate is fixed on the central part thereof. On fixing the boss 2 on the rotary body main body, a fitting part 3 recessed in a circular shape is formed in the vicinity of the center of the rotary body main body and, on the other hand, the boss 2 is, for instance, formed in an octagon shape. The boss 2 is fit into the fitting part 3 for the boss 2 and the fitting part 3 of the rotary body main body is pressed into or drawn to reduce the diameter to obtain the firm combination between both. The boss 2 is also preferable to be one with plural protrusions on the outer periphery.