Section 15 BASE METALS AND ARTICLES OF BASE METAL 73 Articles of iron or steel 73 07 Tube or pipe fittings (for example, couplings, elbows, sleeves), of iron or stee 73 07 11 73 07 11 00 Commodity Code Description 73 07 11 00 00 -- Of non-malleable cast iron 73 07 19 00 00 -- Other 73 07 21 00 00 -- Flanges 73 07 22 00 00 -- Threaded elbows, bends and sleeves 73 07 23 00 00 -- Butt welding fittings 73 07 29 00 00 -- Other 73 07 91 00 00 -- Flanges 73 07 92 00 00 -- Threaded elbows, bends and sleeves 73 07 93 00 00 -- Butt welding fittings 73 07 99 00 00 -- Other