Patent attributes
A rectangular tube (10) is formed such that a pair of side plates (12L, 12R) stand up from the opposite left and right edges of a bottom plate (11) and an extending end of an upper plate (13) extending from the upper edge of the left side plate (12L) substantially in parallel with the bottom plate is placed in contact with the upper end surface of the right side plate (12R). The upper plate (13) has an embossment (18R) projecting in and a pressing portion (14) extending from the upper edge of the right side plate (12R) is placed into contact with the upper surface of the embossment (18R) to prevent an upward movement of the upper plate (13). Thus, the height of the rectangular tube (10) can be reduced by a recessed dimension of the embossment (18R).
