To provide a method of manufacturing a metal body capable of systematically managing manufacturing processes when manufacturing a plurality of rings in which common characteristic patterns are formed, respectively, from a metal board being a material board.

When manufacturing rings from one metal board, the number of twist is determined so that the predetermined characteristic pattern is generated on surfaces of a male ring and a female ring regardless of the sizes. The characteristic pattern depends on the way of laminating a plurality of metal boards, such as the kind and thickness of the metal boards. The number of twist is determined based on the information.