Abstract: The outer surface of an elongated metal component such as a bar is rapidly heated by an induction coil and is thereafter cooled by a quenching spray while being subjected to tensile forces so high that the center portion of the bar approaches yield causing the bar to elongate slightly. The tension on the bar is released thereby obtaining high residual compressive surface stresses in the cooled outer layers of the bar which define an annulus and which shortens the bar slightly until compressive stresses in the surface layers equal the tensile stresses acting on the central sections of the bar thereby greatly improving the fatigue life of the bar.

Abstract: The outer surface of an elongated metal component such as a bar is rapidly heated by an induction coil and is thereafter cooled by a quenching spray while being subjected to tensile forces so high that the center portion of the bar approaches yield causing the bar to elongate slightly. The tension on the bar is released thereby obtaining high residual compressive surface stresses in the cooled outer layers of the bar which define an annulus and which shortens the bar slightly until compressive stresses in the surface layers equal the tensile stresses acting on the central sections of the bar thereby greatly improving the fatigue life of the bar.

Abstract: An apparatus and method for running a compression-type annulus packoff on a drill or other pipe string into an oil or gas well, setting the packoff without rotating the drill string, and then shifting the axial load of the drill string from the packoff to a casing hanger or other suitable well element so that the packoff can be pressure tested under conditions closely simulating normal service conditions. The apparatus comprises an hydraulically actuated well tool that functions both as a means for connecting the packoff to the drill string on which the tool and packoff are run as an assembly into the well, and also as a means for converting hydraulic pressure in the drill string into torque and then transmitting this torque to the packoff for rotating its seal-compressing element, thereby compressing its seal into fluid-tight engagement with the adjacent well elements.