Abstract: A truss fastener for fastening a chord to a tubular member comprises a head and a shank extending from the underside of the head and terminating at a self-drilling distal tip. The shank comprises proximal and distal portions, each having a spiral buttress thread, that are separated by an unthreaded shaft portion. The length L.sub.1 of the self-drilling tip and the distal, shaft and proximal portions of the shank L.sub.2, L.sub.3, L.sub.4 are selected such that L.sub.2 +L.sub.3 is greater than the diameter of the tubular member cavity, L.sub.1 +L.sub.2 is less than the diameter of the tubular member cavity, and L.sub.2 and L.sub.3 are each greater than the total of the thickness T.sub.1 of the wall of the tubular member and the thickness T.sub.2 of the wall of the chord T.sub.1 +T.sub.2. Preferably L.sub.4 is also greater than T.sub.1 +T.sub.2. During installation, the shaft portion freely rotates within the entrance holes in the chord and tubular member as the self-drilling tip drills the exit holes.