A coupling system between tubular members such as tubing, pipes, casing and liner for location in a well bore in which the ends of each tubular have cooperating profiled sections. The profiled sections are arranged coaxially and a radially applied force is applied to form a metal to metal sealed connection. At least one profiled section includes a projection, the projection containing an overhang to the surface of the tubular member, the overhang locking with the opposing profile when the force is applied to provide a coupling with increased burst and collapse rating. Embodiments are provided of arrangements of overhangs such as oppositely directed overhangs and interlocking overhangs.