Patent ID: 10662724

Abstract:
A grip element for gripping a tubular CRA workpiece has a hardened grip surface carrying an array of generally pyramidic die teeth, which may have either pointed or rounded tips, with the configuration of the tooth tips being selected for effective gripping of the CRA workpiece by way of an interference grip, and without unacceptably marking the CRA workpiece. The die tooth density over the grip surface may be selected to minimize accumulation of contaminants between teeth and/or to facilitate removal of accumulated contaminants. The substrate of the grip element may comprise a stainless steel having no free iron, with the grip surface being hardened by nitriding. Optionally, the tips of the grip element may truncated after nitriding to partially expose the stainless steel substrate. In alternative embodiments, the grip element may have a carbon steel substrate with a nitrided grip surface.