Inconel UNS N06601 Pipe Flanges Inconel 601 Flanges are made up of a nickel chromium alloy. The material grads range differently with the composition ratio. The 601 grade has 58% nickel, 21% chromium, carbon, manganese, silicon, sulfur, copper and iron in the composition. There are different types such as socket weld flanges, welded neck flanges, Inconel 601 Slip On Flanges, orifice flanges and so on. The flanges made of this material are strong, corrosion resistant to acids, reducing agents and oxidation and are also harder.