Threaded connections including a pin member and a box member and are mismatched. The pin member and the box member have wedge threads formed thereon with a gap formed between pin and box load flanks and/or pin and box stab flanks of the threaded connection. The mismatch may comprise different flank angles...http://www.google.com/patents/US20070236014?utm_source=gb-gplus-sharePatent US20070236014 - Mismatched flanks for a wedge thread
