Alloy K 500 MONEL® K 500 – W. Nr. 2.4375 / UNS N05500 / ASTM B865

Alloy K 500 MONEL® K 500

Alloy K 500 MONEL® K 500 is a nickel -copper alloy that combines the excellent corrosion resistance of MONEL® 400 with increased mechanical strength and hardness. These superior properties are achieved through the addition of aluminum and titanium and a precipitation hardening heat treatment (aging), which promotes the formation of submicroscopic Ni₃(Ti,Al) particles.

The alloy is widely used for components exposed to marine and chemical environments and is particularly valued for its resistance to oxidation, corrosion, and chloride stress corrosion cracking. It is ideal for applications such as chains, cables, springs, valves, pumps, drive shafts, drilling tool components, and electronic sensors.

Reference standards:

  • ASTM B865 (bars and forgings)
  • NACE MR0175 (Oil & Gas)
  • ISO 9723, ISO 9724, ISO 9725

Chemical composition (%)

Element Content (%)
Nickel (Ni) + Cobalt (Co) 63.0 min
Copper (Cu) 27.0 – 33.0
Aluminum (Al) 2.3 – 3.15
Titanium (Ti) 0.35 – 0.85
Iron (Fe) 2.0 max
Manganese (Mn) 1.5 max
Carbon (C) 0.25 max
Silicon (Si) 0.5 max
Sulfur (S) 0.01 max

Mechanical properties

Form and Condition Tensile strength (MPa) Yield strength (MPa) Elongation (%) Hardness (Rockwell C)
Bars, Forged, Aged 965 – 1310 690 – 1034 30 – 20 24 – 41
Bars, Forged, Annealed 621 – 758 276 – 414 50 – 25 75 – 90 (Rockwell B)
Threads, Annealed and Aged 827 – 1034 621 – 758 30 – 15
Sheet Metal, Annealed and Aged 896 – 1172 621 – 827 25 – 15 24 min.

Heat treatments

  • Solution annealing: 1800°F (982°C) for hot-worked products and 1900°F (1038°C) for cold-worked products, followed by water quenching to prevent the formation of secondary phases.
  • Aging:
    • 1100°F (593°C) for 16 hours, followed by oven cooling to 900°F (482°C).
    • Alternatively, treat at 1000°F (538°C) for 6 hours, with gradual cooling.
  • Process Annealing: Performed at 1400°-1600°F to relieve internal stresses during processing.

Available formats

MONEL® Alloy K 500 is available in the following forms:

Industrial applications

Thanks to its exceptional combination of mechanical and corrosion resistance, MONEL® K 500 is ideal for:

Richiedi Informazioni/Preventivo