A locator/fastener has a first outer member with a precision-machined external body portion, a retention head protruding from a first end, and a multi-diameter throughbore. A fastener, which may take the form of a cap screw, floats in the throughbore of the locator with the threaded portion protruding from a second end of the locator. A receiver has an internal precision-machined surface which contacts the precision-machined body portion of the locator and a threaded bore which receives the protruding fastener. By separating the locating and fastening functions, a quick connect disconnect device is created which does not bind or gall. A hangar system allows a sub-base plate to be attached to a base using the locator-fastener disclosed herein.