A hanging file frame system adapted to accommodate conventional hanging file folders comprising two side rails, two cross member rods and two hoops joined together by four modular joint supports. The side rails are of relatively flat stock with a plurality of breakaway notches in one end. The cross members and the hoops are formed from round bar stock of the same diameter. The cross members are round bar stock of a predetermined length. The hoops are bent from a single piece of stock forming a foot section, uprights at either end of the foot section, two terminating horizontal tangs and barbs on each tang. The modular joint supports are interchangeable and constructed of a resilient but somewhat flexible plastic. The supports comprise minor bosses in a horizonal orientation whenever the hanging file frame is assembled with internal keyways running parallel with the central axis of the minor bosses, and a major boss formed in the side of the support. The barbs on the tangs of the hoops are matched or timed to the keyways. When the tang is inserted into the minor boss, it locks preventing rotation of the hoop and collapse of the system.