As a leading Chinese Monel alloy supplier, AEETHER manufactures and produces different sizes of Monel Alloy R-405 bars. MONEL® nickel-copper alloy R-405 (UNS N04405) is the free-machining grade of alloy 400. Its greater sulfur content enhances machinability. It has essentially the same corrosion resistance and physical properties as alloy 400, but a slightly different range of mechanical properties.