Abstract: An apparatus is disclosed for connecting truss rods and other rigid braces of an irrigation system, wherein the rods include shaft sections with enlarged cylindrical heads at the ends thereof and form part of a truss-type framework supporting a conduit. A coupling assembly for holding a pair of such truss rods together in axial alignment is disclosed and includes a top plate and a bottom plate clamped together with a connecting bolt having a non-circular collar. The collar on the bolt cooperates with similarly shaped holes in the plates of the coupling assembly to prevent relative rotation between the plates and also between the bolt and the coupling assembly. The bolt includes a head with a hexagonal drive recess for use with an appropriate driving tool.