Monel® K-500 (UNS N05500)
Precipitation-Hardenable Nickel-Copper Alloy
What Is Monel® K-500?
Monel® K-500 (UNS N05500) is a precipitation-hardenable nickel-copper alloy that combines the excellent corrosion resistance of Monel 400 with substantially higher strength and hardness developed through age-hardening. Small additions of aluminum and titanium produce a coherent gamma-prime precipitate that increases yield strength to roughly three times that of Monel 400.
Like Monel 400, the K-500 grade is highly resistant to seawater, brine, and many reducing acids, and it remains essentially immune to chloride stress corrosion cracking. After age-hardening, it offers a strong combination of corrosion resistance, mechanical strength, and fatigue performance — and unlike Monel 400, it is non-magnetic above approximately -150°F.
Monel K-500 is widely specified for marine fasteners, pump and valve internals, oilfield tooling, and any application where Monel 400-level corrosion resistance is needed but higher strength is required.
Standards and Designations
Common Names & Cross-References
Designation | Value |
|---|---|
Trade Names | Monel® K-500, Alloy K-500, K-Monel, Nicorros® Al |
UNS | N05500 |
German (W.Nr. / DIN) | 2.4375 — NiCu30Al |
British Standard | BS 3076 NA18 |
EN (Europe) | NiCu30Al |
Federal | QQ-N-286 |
AMS (Aerospace) | 4676 |
Properties of Monel® K-500
Monel® K-500 Chemical Composition
|
Element |
Composition (%) |
|---|---|
| Nickel (Ni) + Cobalt | 63.0 min |
| Copper (Cu) | 27.0 – 33.0 |
| Aluminum (Al) | 2.30 – 3.15 |
| Titanium (Ti) | 0.35 – 0.85 |
| Iron (Fe) | 2.0 max |
| Manganese (Mn) | 1.5 max |
| Silicon (Si) | 0.5 max |
| Carbon (C) | 0.25 max |
| Sulfur (S) | 0.010 max |
Typical Mechanical Properties
|
Property |
Annealed |
Age Hardened |
|---|---|---|
| Tensile Strength | 100 ksi (690 MPa) | 160 ksi (1100 MPa) |
| Yield Strength (0.2%) | 50 ksi (345 MPa) | 100 ksi (690 MPa) |
| Elongation (in 2 in.) | 35% | 20% |
| Hardness | Rockwell B 85 | Rockwell C 27-35 |
About Monel® K-500
Key Features & Advantages
- High strength developed through age-hardening — yield strength typically 3x that of Monel 400
- Corrosion resistance equivalent to Monel 400 in most environments
- Highly resistant to chloride stress corrosion cracking
- Excellent performance in seawater, brine, and many reducing acids
- Good fatigue and wear performance after aging
- Non-magnetic at temperatures above approximately -150°F
- NACE MR0175 approved for sour oil & gas service
Common Applications
- Marine shafts, chains, fasteners, and propeller hardware
- Pump shafts, valve components, and impellers
- Oilfield tools, instrumentation, and downhole hardware
- Wear and fatigue-sensitive components in corrosive service
- Springs and high-strength corrosion-resistant fasteners
- Naval submarine hardware and fittings
Primary Markets Served
- Marine & Offshore
- Oil & Gas (sour service)
- Defense & Naval
- Chemical Processing
When to Specify Monel® K-500
- Monel K-500 vs. 400 — Same corrosion resistance; K-500 has 3x the yield strength after age-hardening. Specify K-500 for fasteners, shafts, and any component where strength matters.
- Monel K-500 vs. 17-4 PH stainless — K-500 has dramatically better seawater and HF performance. 17-4 PH has higher strength and lower cost for non-marine service.
- Monel K-500 vs. Inconel 718 — 718 has higher strength and better elevated-temperature performance. K-500 has better seawater and HF resistance and is more economical for marine service.
- Monel K-500 vs. duplex/super duplex stainless — K-500 is the premium choice for severe seawater pump shafts and fasteners. Duplex is more economical but doesn’t match K-500’s HF performance.
Why Source 21?
- ISO 9001-certified quality system with full chemistry and mechanical traceability on every shipment
- Multi-million dollar national inventory across stainless, nickel alloys, copper, and brass
- Strong domestic and international mill relationships, including premium specialty mill partnerships
- In-house slitting, edging, leveling, and cut-to-length capabilities
- Contract programs, blanket orders, and vendor-managed inventory (VMI) for production accounts
- Responsive technical support for tight-tolerance and certification-driven work
Request a Quote
Contact Source 21 today for Monel K-500 pricing, availability, and processing options. Our team responds quickly, asks the right questions, and gets you accurate quotes on real material — not vague placeholders.
Call 631-821-1101 or request a quote online to get started.