Swinging piston manufacturing method

A method of manufacturing a piston of the swing piston is formed integrally with the body of the piston body from the plate-shaped blades projecting piston configuration, followed by the plate-shaped blade formed by processing the side surface of the swing piston, wherein, in the plate-shaped blades forming radial end face constituting a positioning reference of the axis of the piston relative to the recesses or projections in the lower support inner or outer diameter of the piston while the vane is radially inserted into the support member in the reference state by having two annular grinding wheel surface facing, with two pair of side surfaces on the blade processing.