Hughes Xtra threads are Non Preferred Rotary Shoulder Connections which have a V‐038R thread form. Thread Check, Inc. offers the complete range of Hughes Xtra Hole Thread Plug and Ring Gages. Our engineering staff have served on various API gaging subcommittees and have worked in the energy industry for many decades. Thread Check's expert engineers can assist you with engineering and building custom gages. Thread Check is a proud member of the American Petroleum Institute.