To provide a strong load moment arm fixable to the end of the end face of an aluminum longitudinal section.

In this load moment arm, an outer surface 3 is surrounded by a frame at the end of the aluminum longitudinal section 2, and the frame is brought into contact with all four outer surfaces 3 without a clearance. The frame has a lower end contact surface extending at the height of the end face of the aluminum longitudinal section 2 on two outer surfaces 3 opposed to each other. At least one overturning ridge 10 disposed on the same plane as the end face of the aluminum longitudinal section 2 is provided on the other two outer surfaces 3 opposed to each other. A connection element 6 fixed to the end face is brought into contact with the end face, overturning ridge 10, and lower end contact surface of the frame, and is fixed to at least the contact surfaces.