BC-3N PROTECTOWIRE Iron Zink Plated Beam ClampBC 3N PROTECTOWIRE Iron Zink Plated Beam Clamp Clamp Assembly, Beam, Iron Zinc, Type N (Nylon Clip) The BC 3 Series Beam Clamp assembly consists of a beam clamp, nylon WAW Clip (type N) or a polypropylene WAW Clip (type P), and snap button. The BC 3 utilizes a heavy duty zinc plated clamp that is suitable for both indoor and outdoor use. These versatile fasteners may be used for mounting Protectowire on cable trays, conveyors, angle irons, I beams,