Top lock jam nut apparatus and method

A jam nut apparatus for fastening to a threaded end of a bolt to secure said bolt wherein said threaded end has first handed threads, comprising:

• a locking nut having an internal nut passageway with nut internal threads, said nut passageway having a first passage-way end with an inwardly extending locking flange,
• a bolt end cap having a tubular cap side wall, said cap side wall having an open end with a locking edge and an inner surface with first handed internal threads, for engagingly receiving said threaded end of said bolt, said cap also having an outer surface with second handed external threads opposite to said first handed thread direction, external threads onto which said locking nut threads engagingly fasten,
• wherein said locking nut threads are oriented in said second handed direction,
• said locking edge being at a free end of a reduced diameter tubular locking rim portion extending axially from said cap open end, wherein said locking flange fits around and over said locking rim portion of said cap.