In this paper, T-joints of a new joint system (Y-truss) using rectangular hollow sections are subjected to an experiment to determine the local deformation and stress of the joint and give an equation for estimating the joint strength. This new joint system has been developed to give desired strength and rigidity to the joints without stiffening the connections. The experimental findings about the new truss system are as follows : 1) The strain distribution in the bracing leg is entirely different from that in the conventional system. 2) The ultimate strength of T-joints of this new joint system is greater than that of conventional joints and can be estimated by the equation proposed in this paper with high enough accuracy.
