| http://www.w3.org/ns/prov#value | - The drillstring of claim 17 further comprising:wherein the central passageway contains a wire spring, and wherein the coating is a PTFE contained coating, and wherein the assembled elements provide an ungrooved land area, near the drill bit, and of the bit diameter, and wherein the assembled elements provide a drill shaft with compressive, tensile, and torsional integrity.
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