QQ-N-281 - Nickel 400 / Monel 400 Federal Specification
QQ-N-281 includes UNS N04400 in various product forms, such as bar, plate, sheet, strip, wire, forgings, and structural or special shapes. This federal spec provides guaranteed quality, strength, and corrosion resistance in aerospace, marine, and industrial applications.
Overview of Nickel 400 per QQ-N-281
Nickel 400, as specified in QQ-N-281, is a nickel-copper alloy with a solid solution combination that combines excellent mechanical properties with excellent performance in corrosive environments. It remains tough over a wide range of temperatures and has good performance in seawater, hydrofluoric acid, sulfuric acid, and alkaline solutions.
It cannot be heat-treated for hardness. Its cold working properties give it strength. Its combination of ductility, toughness, and lack of magnetism make it suitable for critical applications.
Typical Composition:
Ni ≈ 63–70 % Cu ≈ 28–34 % Fe ≤ 2.5 % Mn ≤ 2 %
Applications of Nickel 400 per QQ-N-281
This Specification is used across multiple critical sectors:
- Marine systems: propeller shafts, pump shafts, and seawater valves
- Chemical and process industries: heat exchangers, piping, and reaction vessels
- Oil & gas: pump rotors, fittings, and downhole components
- Aerospace and defense: fasteners and structural hardware
- Power generation: condensers, heat-exchanger tubing, and brine systems
Related Specifications
SHEET & PLATE
Sheets and plates for high-temperature aerospace and industrial applications.
BARS & FORGINGS
Bars and forgings designed for high-strength, creep, and fatigue-resistant components.
Certified Material for Critical Service
Monel 400 material from Fighter Jet Metals is:
- Certified to AMS 4544, AMS 4675, AMS 4730, ASTM B164, and QQ-N-281
- Supplied with complete Material Test Reports (MTRs) and heat traceability
- Processed under AS9100 & ISO 9001 quality systems
- Verified for aerospace, marine, and chemical processing service
This guarantees mechanical consistency, dimensional reliability, and corrosion performance across all supplied forms.