Material Family

Nickel-Copper Alloy (Free-Machining, Sulfur-Bearing) Coil/Strip

The coiled form of the free-machining Monel grade.

Distinguishing Feature

Enhanced Machinability for high-speed automatic screw machine and CNC lathe operations.

This is the primary reason to specify R-405 over standard Monel 400 coil.

Common Forms & Tempers

Forms: Cold Rolled Coil (Strip), Annealed Pickled Coil.
Temper: Typically supplied in Annealed (Soft) temper. Also available in Half-Hard or Hard tempers for parts requiring higher strength post-machining.

Supplied soft for optimal machinability. Can be cold drawn to wire for screw machining.

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
S: 0.025 - 0.060

The key difference from Monel 400 is the intentional addition of Sulfur (S). This forms manganese sulfide inclusions that act as chip breakers, enabling smooth, fast machining.

Mechanical Properties (Annealed Coil, Room Temp)

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

Mechanical properties are nearly identical to Monel 400 in the same temper.

Coil Physical Specifications (Typical)

Thickness: 0.5mm - 3.0mm (0.020" - 0.125") – often processed into wire.
Width: 10mm - 300mm (0.4" - 12")
Coil I.D.: 300mm, 405mm, 508mm (12", 16", 20")
Coil Weight: 50kg - 1000kg

Often supplied as strip for blanking into machining stock or directly drawn into wire rod coils for screw machines.

Machinability Rating

Excellent. Typically rated at 70% on the free-machining brass scale (where 100% is C36000 brass). Similar machinability to free-machining stainless steel 303.

Allows for high production speeds, excellent surface finish, and extended tool life compared to Monel 400.

Corrosion Performance Note

The sulfur addition can marginally decrease corrosion resistance in certain severe, hot acid environments and slightly reduce ductility compared to low-sulfur Monel 400. Performance in seawater and most typical marine/chemical applications remains excellent.

For critical welded structures or the most severe HF service, Monel 400 coil is preferred. For machined parts, R-405 is standard.

Key Standards (Strip/Coil)

ASTM B164 / ASME SB-164 (Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire – includes R-405). Coil may be supplied to this spec or to customer agreements based on B127 with S control.

The sulfur-controlled chemistry is the critical procurement requirement.

Typical Coil Applications

• Mass-produced Fasteners: Screws, nuts, bolts, studs for marine and chemical applications.
• Valve Components: Stems, seats, bushings, fittings.
• Pump & Shaft Components: Sleeves, shafts, impeller nuts.
• Electrical & Connector Parts: Terminals, contacts, housings.
• General Machined Parts for seawater systems.

The dominant material for corrosion-resistant, free-machining components where Monel 400's base properties are required.