Abstract: An apparatus for axially joining two tubular members of differing diameters in which a band of metal is passed around the adjacent ends of the members and circumferentially stressed by means of reinforcing, notched bars secured to the band, to conform with the outer surfaces of the members. The clamping device may be used to make a strong gas or sound leak-proof joint between two substantially incompressible tubular members in which event the band of metal is substantially stretched plastically so that it conforms intimately with the outer surfaces of the tubular members. The clamping device may also be used to make a joint which is not necessarily gas-leak-proof and is more easily disconnected by not stressing the band of metal to the point where it goes through a substantial amount of plastic yielding.