Abstract: A thermoplastic cylindrical clamp is manufactured by heating a flat sheet of thermoplastic material, thermoforming the softened sheet over a mold having two parallel and semicylindrical shapes with a narrow planar space between them and a coplanar flange surrounding, trimming the thermoformed sheet so the semicylinders are open at each end, locally heating the narrow planar portion between the semicylinders to the softening point, bending the softened portion so the semicylinders form a complete cylinder and cooling the part in the cylindrical shape.