Abstract: A coupling assembles structural members at least one of which has an opening and another of which has grooves extending along its outer surface. The coupling has two yieldably spaced body portions inserted within the opening of the one structural member. Each body portion has a claw which protrudes from the opening in the one member and is received in a groove of the other structural member. A fastener extends between the yieldably spaced body portions for moving the body portions until each claw grips a side of the groove in which it is received to assemble the structural members. The fastener also connects the structural member having the opening to the coupling and the claws and grooves have cooperatively inclined gripping surfaces for drawing the one structural member into firm butting engagement with the other when the claws grip the grooves.