Structural body formed by friction stir welding of hollow extruded frame members

A structure body, characterized in that

• the structure body comprises a first member having two sheet face plates and one of said two sheet face plates and another of said two sheet face plates being connected by a rib, a second member joined to said first member, with the joining being carried out according to a friction stir welding to a joining portion of said one of said two sheet face plates of said first member and said second member;
• at least one visible outline lines of a connection portion of said rib and a respective one of said two sheet face plates of said first member is comprised of a curved line which is recessed in a solid side of said first member;
• said curved line is arranged in a side of said one of said two sheet face plates of said first member;
• said curved line is connected to a linear line which is inclined in a side face of said rib;
• said one of said two sheet face plates of said first member has a horizontal line which is connected to said curved line;
• and
• said rib has a perpendicular line with said horizontal line of said one of said two sheet face plates of said first member and is connected to said linear line which is inclined in a side face of said rib.