A corner key (10) for connecting profiles (12, 14) together and a
frame work assembly formed of such corner keys (10) and (profiles (12, 14). Each profile (12, 14) has an anchoring channel (16, 18), a drainage and venting passage (20, 22) and a securing bore (24, 26). The corner key (10) has two adjacent inner corner faces (28, 30), two adjacent outer corner faces (32, 34), and opposite inner and outer side corner faces (36, 38). Tabs (40, 42) on the inner corner faces (28, 30) guide the
coupling of the profiles (12, 14). Fasteners (48, 50) are inserted through the outer corner faces (32, 34) in corner key bores (44, 46) and in the bores (24, 26) of the profiles (12, 14). A drainage and venting passage (52) in the corner key (10) communicates with the drainage and venting passages (20, 22) of the profiles (12, 14).