Monel 400 (UNS N04400 / W.Nr. 2.4360) Pipes: A Comprehensive Analysis of Composition, Properties, and Engineering Applications Monel 400, designated as UNS N04400 or W.Nr. 2.4360, represents a nickel-copper solid-solution alloy renowned for its exceptional corrosion resistance in aggressive environments, particularly those involving seawater, hydrofluoric acid, and reducing media. Although occasionally misclassified as a