Material Family

Nickel-Copper Alloy (Solid-Solution Strengthened)

The classic nickel-copper alloy bar with a unique performance profile.

Common Forms (Bar)

Hot Rolled, Forged, or Cold Finished Rounds, Hexagons, Squares. Also as Forging Billet.

Available in a wide range of diameters and sections for machining and forging.

Chemical Composition (Typical wt.%)

Ni: ≥ 63.0 (Balance)
Cu: 28.0 - 34.0
Fe: 2.5 max
Mn: 2.0 max
C: ≤ 0.30
Si: ≤ 0.50

The high nickel-copper ratio is the source of its unique corrosion resistance in seawater and reducing environments.

Mechanical Properties (Annealed, Room Temp)

Tensile Strength (Rm): 480 - 620 MPa
Yield Strength (Rp0.2): 170 - 345 MPa
Elongation (A): 35 - 50%

Offers good strength and excellent ductility, making it very tough and forgiving for machining.

Physical Properties

Density: 8.80 g/cm³
Melting Range: 1300 - 1350 °C
Useful Service Range: Cryogenic to about 540°C (1000°F).

Maintains good mechanical properties across this entire range.

Key Corrosion Resistance Attributes

• Excellent resistance to seawater and fast-flowing brackish water, resisting cavitation erosion and biofouling.
• Excellent resistance to hydrofluoric acid (HF) at all concentrations and temperatures, especially in the absence of air.

• Good resistance to sulfuric (H₂SO₄) and hydrochloric (HCl) acids under reducing conditions.

• Good resistance to alkalis, salts, and organic acids.

• Poor resistance to oxidizing acids (e.g., nitric acid, HNO₃) and aerated solutions with oxidants.

A specialist alloy bar for seawater and specific acid services, especially hydrofluoric acid.

Key Standards (Bar)

ASTM B164 / ASME SB-164 (Standard Specification for Nickel-Copper Alloy Rod and Bar), AMS 4544 (Aerospace)

ASTM B164 is the primary specification for bar (rod) products.

Common Sizes & Conditions

Diameter/Thickness: 5mm (0.2") up to 300mm (12")+ for hot rolled/forged.
Condition: Hot Rolled, Annealed, or Cold Drawn. Available in various tempers (e.g., Annealed, Half Hard, Hard).

Supplied in conditions suitable for machining (Annealed) or for high-strength applications without heat treatment (Cold Drawn).

Machinability

Machinability Rating: ~40% (in Annealed condition). More machinable than many nickel alloys, but gummy. Requires sharp, positive-rake tools and adequate feeds to break chips. Free-machining grade Monel R-405 is available for high-speed production.

For high-volume machining, specify R-405 (UNS N04405) which contains added sulfur.

Typical Bar Applications

• Marine Engineering: Propeller shafts, pump rods, valve stems, fasteners (bolts, studs), boat fittings.
• Chemical Processing: Stirrers, shafts, valve trim for HF and reducing acid service.
• Oil & Gas: Components for seawater cooling systems, umbilicals, non-magnetic tools.
• Power Plants: Feedwater heater components, fasteners for corrosive environments.

The historic and premier bar material for critical seawater-exposed components and HF service.