Abstract: The problem of firmly gripping a cylindrical component over a range of permitted diameters is solved by providing a protrusion on the surface of a cantilevered seat, the seat being substantially complementarily curved to accommodate the cylindrical component. In a preferred embodiment of the present invention a clamp for holding a cylindrical component is provided comprising at least one curved seat having at least one protrusion, the curved seat being cantilevered by a first end. The protrusion is configured to contact the cylindrical component under load such that a concentrated load is exerted on the curved seat between a first end and a second end causing the curved seat to be elastically deflected.

Abstract: A clamp for a cylindrical workpiece useful for a tube welder includes two clamping plates arranged to move in the same plane to engage the workpiece in a central opening formed by cooperating indentations in the clamping plates and both clamping plates are provided with at least one supported beam flexible member for pressing against the workpiece and accommodating variations in the diameter of the workpiece from the nominal diameter.