Abstract: A space frame including at least two elongate structural frame elements arranged side by side and being interconnected by a plurality of elongate struts spaced along the length of the elements, each structural frame element comprising an elongate hollow body having one or more strut connection nodes located along its length at predetermined positions, each connection node being in the form of a socket extending internally of the element, the socket comprising a socket wall depending from one side wall of the hollow body, the socket wall defining a socket recess and being formed by hydro-forming from said one side wall of the hollow body, each opposite end of each strut being in the form of a plug received within the socket defined by a co-operating respective connection node. The hydro-forming process may include the use of any type of pressurised hydraulic fluid.

Abstract: A process for hydroforming an elongate tubular structural member in a mould die, the structural member having portions spaced along its length which have different circumferential dimensions, a first of said portions having a first cross-sectional shape defining a minimum outer circumferential dimension C.sub.1 and a second of said portions having a second cross-sectional shape defining a maximum outer circumferential dimension C.sub.2, the process including the steps of: (i) selecting a precursor tube of constant cross-sectional shape and constant outer cross-sectional dimension along its length and having an outer circumferential dimension C.sub.0 which is greater than or equal to C.sub.1 and being of a cross-sectional shape which can be located within said first cross-sectional shape, and selecting the wall thickness S.sub.0 of the precursor tube so as to fall within the range S.sub.0 .ltoreq.S.sub.1 and S.sub.0 .gtoreq.S.sub.2 wherein S.sub.