Hollow member

摘要

A lightweight hollow member having excellent stiffness and impact properties and which is suitable for automotive parts due to having a high strength such as at least 780 MPa and a complicated shape is provided. A hollow member 11 has a hollow steel body 14. The body 14 is constituted by a single member at least in the lengthwise direction. The body 14 has a flat cross section having at least a portion with a maximum outer dimension L1 and a portion with an outer dimension L2 shorter than the maximum outer dimension L1. The body 14 has a twisted portion in a portion of its length. The angle of intersection between an imaginary plane 15a including the portion having the maximum outer dimension L1 in a first portion 15 present on one side of the body 14 in the lengthwise direction with the twisted portion 17 as a border and an imaginary plane 16a including the portion with the maximum outer dimension L1 in a second portion 16 present on the other side in the lengthwise direction of the body 14 with the twisted portion 17 as a border is at least 4 degrees. The twisted portion 17 has a tensile strength of at least 780 MPa.