Abstract: For use in constructing a framework comprising a plurality of elongate rectangular-section elements such as square-section tubes, a kit comprising a plurality of clamp members (such as A) each having at least one first part (10) defining a portion of a socket, a second part defining a portion of a recess or channel, and fixing means (15) whereby the clamp member can be secured to a like clamp member to form a clamp assembly. Selected ones of the clamp members of the kit can be secured together to form a plurality of clamping assemblies, the number of different clamping assemblies constructable being greater than the number of clamp members.At least one outer wall of a clamp member can have a depression (22) for a head (24a) of a fastener (24) whose stem projects outwardly of the clamp member, either via an aperture (23) therein or via a gap between adjacent clamp members, to enable auxiliary fittings such as wall panels etc. to be secured to the framework.