Patent ID: 7219933

Claim:
A hollow product comprising two hollow members joined to each other for allowing fluid to flow therethrough, wherein one of said two hollow members is formed with a joining portion by spinning working, and either one of said two hollow members is connected to an engine, wherein said joining portion of said one of said two hollow members is formed by the spinning working so as to project radially outward at an axially intermediate portion of said one of said two hollow members wherein said one of said two hollow members is disposed within the other of said two hollow members, and said joining portion of said one of said two hollow members formed by the spinning working is joined to said other of said two hollow members by friction welding carried out by relatively rotating said one of said two hollow members and said other of said two hollow members, wherein said joining portion includes an oblique surface prior to joining said two hollow members, and is joined to said other of said two hollow members by friction welding, wherein said two hollow members are joined to form an exhaust pipe.