A sag bend portion is formed in a longitudinal part of the load beam and bent in a thickness direction. The load beam includes a first portion and a second portion bordering the sag bend portion. Roots of outrigger portions are secured to the load beam by weld portions. A slit portion is formed around each of the weld portions. The slit portion includes an arc-shaped slit and a pair of extension slits. An outrigger support portion is formed inside the slit portion. The outrigger support portion extends in a direction different from that of the second portion of the load beam with respect to a cross section along the longitudinal direction of the load beam in the thickness direction.