Abstract: A corner connection fitting (1) for a frame is disclosed. The corner connection fitting (1) interconnects front frame members (18) to base frame members (13). The front frame members (18) are rotatable to an outer, open position so as to allow the picture (21) to be easily inserted or adjusted within the frame assembly.

Abstract: Hollow frame members (1, 11), having openings (2, 12) to hold a picture along its longitudinal direction, and having connection faces (3, 13) cut to 45.degree. at its ends, receive each insertable leg part of an L-shaped corner connection fitting (5, 15). The frame members (1, 11) connect to each other in perpendicular relationship to form a square form. One stage or two stage engaging means consisting of stoppers (6, 16) and stopper holes (4, 14) at the corner part of the frame members enable expansion of the frame surface, allowing for assembly or disassembly, and easier replacement of pictures. Spring parts or guides (7, 17) are formed on the corner connection fittings (5, 15), to eliminate looseness of the frame members, and to make insertion and withdrawal smoother. The stoppers (6, 16) can be formed as one body with the corner connection fittings (5, 15) with a resin having elasticity to make the manufacturing of the corner connection fitting easier.