Abstract: A structural member of the kind including a strip of metal sheet folded over onto itself at its lateral edges so that the member has respective boxed edge formations (20, 21) which extend between a pair of notional substantially parallel planes and are linked by a web (30). At least one of the boxed edge formations defines a longitudinally extending ridge (40) at one of the planes and, behind the other plane; an outwardly open longitudinally extending groove (34) complementary to the ridge, whereby the structural member may be stacked on another similar member and the stack be laterally stabilized by co-operation of the groove (34) on one member and the ridge (40) on the other.