Anti-rotation lock asembly includes a male threaded member that may be releasably locked in any desired axially adjusted position relative to a mating female threaded member by means of one or more wedge keys that are forced axially into notches in an end face of the female threaded member and radially against flats or keyways on the male threaded member. Surrounding the male member is a key retaining ring which retains the wedge keys on the male member when the wedge keys are disengaged from the female member to permit relative rotation between the male and female members for adjustment of the male member in or out relative to the female member. The wedge keys are retained in radial slots in the retaining ring which prevent relative axial movement between the wedge keys and retaining ring while permitting limited radial movement therebetween.