Abstract: A device for retaining tubular inner and outer members together in a well allows the members to be pulled apart with a sufficient shear out force. The members have mating retaining and reaction groooves. The retaining groove has a deeper portion joining a shallower portion which is bounded by a shearing side wall. The reaction groove has a shearing side wall which opposes the shearing side wall of the retaining groove when the inner and outer members are fully inserted together. A solid elastomeric ring is carried within the retaining groove. The ring locates in the deeper portion when the inner and outer members are being pushed together. When a pulling apart force is applied, the shallower portion slides relative to the ring until the ring locates in the shallower portion and is contacted by the opposed shearing side walls.