Patent ID: 7178303

Claim:
A hollow frame member adapted to be friction stir welded, comprising: said hollow frame member arranged against another hollow frame member to be subjected to a friction stir welding, said hollow frame member comprising a first plate, a second plate substantially in parallel to said first plate, and plural ribs for connecting said first plate and said second plate, said hollow frame member further comprising a third plate that connects a midway portion of said first plate of said hollow frame member and an end portion of said second plate of said hollow frame member, wherein an end portion of said first plate of said hollow frame member projects beyond said end portion of said second plate of said hollow frame member, and said end portion of said first plate is a portion in which by inserting a rotary tool from an upper portion of said second plate of said hollow frame member of said hollow frame member to said end portion of said first plate of said hollow frame member, the friction stir welding is carried out at an abutted portion which is formed between said end portion of said first plate of said hollow frame member and an end portion of a plate of said another hollow frame member using said rotary tool.