A mechanical connector for oil and gas well apparatus applies a predetermined preload across the connection, the preload being adapted to accommodate relatively large dimensional tolerances in the loadpath of the connector preload by placing a component with a
low modulus of elasticity within that load path. In one embodiment, the connector comprises fingers (3) of a pair of
pipe flanges (1, 1′), a stationary
retainer ring (14) against which a finger reaction surface (13) is pressed, a runner ring (15) located outside the fingers and movable lengthwise along the fingers by an
actuator (16), the
retainer ring and the runner ring having an elasticity that is so large that deviations in their elongation only have a small influence on the
retainer ring and the runner ring
radial pressure against the fingers and clamping forces of the fingers against the flanges. In a second embodiment, the connector comprises dogs (103, FIG. 4) located around the circumference of a first tubular
joint component, a follower located outside the dogs (103) and movable axially of the dogs, the
low elastic modulus component being a ring located in the loadpath below the dogs. In a third embodiment, the connector comprises a lockdown mechanism acting between nested components, the
low elastic modulus component being an insert comprising a load shoulder transferring loads between the nested components.