High precision fiber optic connectors

A fiber optic cable connector (600) comprises     two mating housing halves (601,604), provided with interlocking latch (166) and lug (168) means for interlocking to constitute a connector housing, said housing halves having external portions at first ends jointly to provide an external thread, and cooperating to provide a housing opening at their opposite ends;     a strain relief (301,331) firmly attached to a first end of a fiber optic cable and having one end (311,332) shaped and sized to be grasped by said interlocked housing halves;     a nut (146) threaded onto the threaded external portions positively to retain the strain relief;     a ferrule terminating said fiber grasped firmly inside said interlocked housing halves such that the terminal end of said ferrule is directed forwardly and positioned within said opening;     said housing halves (601,602) each having a straight longitudinal groove (603,604) on an exterior surface, said groove having an open end at the rim of said opening of said connector, and said exterior surface of each of said housing halves being reduced in dimensions on one side (605) of said groove so as to be slightly smaller than the interior of the unreduced portion (601,602) on the other side of said groove.