Abstract: A pipe coupling having a pair of opposed, semi-circular collar halves to be attached via fasteners for clamping the halves together on abutting ends of collinear pipes. The pipe ends have circumferential grooves engaged by ridges on an inside of collar half. A pair of parallel reinforcing wings extend radially by a varying height on an outside of the collar halves, along the axial edges, providing rigidity and strength to the pipe coupling. The wings increase in radial height from the circumferential ends adjacent the tabs to a maximum at the center of the coupling. The wings thereby distribute unequal forces, which are concentrated at the center, to achieve equally distributed deformation with such forces, thereby reducing the possibility of the ridges disengaging the grooves due to concentration of deformation at a local area.