Abstract: An interconnection for oil field tubular goods operates in a self sealing manner in response to internal pressures which might otherwise cause leakage through couplings or joints. Each coupling sleeve includes an interior fulcrum ring fitted between the nose ends of the tubing or casing, and centrally engaging a fulcrum seating zone centered in the sleeve. Internal pressures tend to bend the ends of the fulcrum ring outwardly toward clearance or relief spans on each side of the fulcrum zone. This deflection increases the contact force and enhances the metal-to-metal seal between the end faces of the fulcrum ring and the pin end faces.