Abstract: A fence system, using extruded bars of T-shaped cross-section to form posts and rails, and a plurality of connectors to connect the T-bars. The connectors have vertical and horizontal V-channels within which the T-bars are secured. Each V-channel has a pair of sides which meet at a vertex, and an open end. A plurality of clamping mechanisms each include a cross plate which extends across the open end of the V-channel to hold the T-bar therein, and a pair of J-bolts which secure to both the V-channel sides and the cross plate. An inverted U-channel extends between the cross plate and the T-bar to directly engage the T-bar and hold it tightly against the vertex of the V-channel. The T-bar has a plurality of spaced protuberances thereon. A transverse pin extends across the U-channel so that when the clamping mechanism is engaged with the T-bar, interference between the transverse pin and the protuberances prevent the T-bar from slipping longitudinally within the V-channels.