A deformable mechanical pipe coupling is disclosed. The coupling is formed from an arcuate band that surrounds and defines a central space. The band has first and second ends in facing relation. arcuate surfaces that engage outer surfaces of the pipe elements extend lengthwise along the band. The arcuate surfaces have radii of curvature greater than the radii of curvature of the pipe element outer surfaces, allowing pipe elements to be inserted within the central space. The band has adjustably tightenable connection members mounted at each end. When the connection members are tightened, the ends are drawn toward one another, and the arcuate surfaces on the band deform and conform to the radius of curvature of the outer surfaces of the pipe elements.