A pipe body, wherein the pipe body (10) has a welded portion (11) at both ends of the pipe body, aligned in a widthwise direction of the pipe body (10). The thickness of the welded portion (11) decreases gradually from the inside to the outside of the pipe, and an outer end of the welded portion (11) is located at a center portion of the pipe body (10) in a thickness direction. The configuration of the welding structure enhances the strength of the welded portion of the pipe, so that the pipe will not crack easily when it is reworked by flaring or bending, thus having high reworkability. In addition, a pipe (100) made of the pipe body (10) and a method of making the pipe (100) are disclosed.