Profile: K&B Duct Systems is mainly involved in supplying industrial ductwork systems & parts. We offer angle rings, automatic blast gates, ball joints, blast gates, diverter valves, elbows - one piece, flex hose, floor sweeps, rubber flex hose, no loss stackheads, and special angle rings. Pressed and rolled steel angle rings are used widely in joining ductwork together in dust and fume control work. All rings are of black steel, and unpainted. 3" through 14" diameter angle rings are press formed, and above 14"diameter are roll formed and welded. They are available with or without holes - bolts not included. Larger angles, channels, bars and other sizes rolled to order in steel, aluminum, stainless and other alloys are also available. We also provide square and rectangular flanges. All angle rings and flanges are punched on automatic equipment.