Nickel Alloy Monel 401
UNS N04401
Monel 401 (UNS N04401) is a nickel-copper alloy with controlled electrical resistivity, pairing Monel-family corrosion resistance with predictable resistance behaviour.
Reference datasheet — Monel 401 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
Monel 401 tempers and conditions
Monel 401 is supplied in 6 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard stocked condition: maximum ductility for stamping, drawing and coil winding, most stable resistivity. | 170 | 470 | 42 | 115 HB | — |
Quarter hard | Choose when slightly higher stiffness and better blanking edge quality are needed but forming is still required. | 350 | 550 | 25 | 150 HB | 3.6 % IACS |
Half hard | Balance of strength and remaining bend ductility for contacts, clips and formed terminals. | 470 | 620 | 15 | 185 HB | 3.5 % IACS |
Stress relieved | Cold-worked material given a 260–370 °C stabilizing treatment to lock in resistance value and reduce residual stress/drift. | 600 | 700 | 8 | 210 HB | 3.5 % IACS |
Hardened | Maximum strength and hardness from cold work; use for flat springs, straight wire and machined parts needing good chip control. | 620 | 730 | 6 | 20 HRC | 3.5 % IACS |
Spring Temper | For coil and flat springs, contact fingers and resistance elements needing high elastic limit. | 720 | 830 | 3 | 22 HRC | 3.5 % IACS |
What is Monel 401?
Monel 401 (UNS N04401) is a nickel-copper alloy with controlled electrical resistivity, pairing Monel-family corrosion resistance with predictable resistance behaviour. It is supplied as wire, strip and rod in annealed, quarter-hard, half-hard, full-hard, spring and stress-relieved conditions for resistors, thermostat parts and corrosion-resistant springs. Annealed values are 170 MPa yield, 470 MPa tensile, 42 % elongation and 115 HB (65 HRB), with service to about 425 °C and high cold formability (score 85). It work-hardens rapidly and machines slowly; where resistivity control is not required, Monel 400 is cheaper and more available. Monel 401 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 85% of nickel alloy grades. It melts at 1,260°C (2,300 °F). Monel 401 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 96% of nickel alloy grades. Elongation at break is 42% and the elastic modulus is 160 GPa (23.2 Msi).
What is Monel 401 used for?
- electrical resistors
- thermostat components
- corrosion-resistant springs
Advantages
- Low embodied carbon — 7.5 kg CO₂/kg, better than 96% of nickel alloy grades
- Forms and bends easily — 85/100, better than 95% of nickel alloy grades
- High electrical conductivity — 3.6 % IACS, better than 92% of nickel alloy grades
- Easy to machine — 30/100, better than 90% of nickel alloy grades
- Conducts heat well — 21 W/m·K (12.1 BTU/hr·ft·°F), better than 88% of nickel alloy grades
Limitations
- Low strength — 170 MPa (24.7 ksi), worse than 96% of nickel alloy grades
- Low stiffness — 160 GPa (23.2 Msi), worse than 92% of nickel alloy grades
- Limited service temperature — 425°C (797 °F), worse than 90% of nickel alloy grades
Monel 401 properties
Typical room-temperature values for Monel 401-ANN; bars are the position among nickel alloy grades.
Physical3
Monel 401 has a density of 8.86 g/cm³ (0.32 lb/in³), heavier than 85% of nickel alloy grades. It melts at 1,260°C (2,300 °F).
Mechanical14
Monel 401 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 96% of nickel alloy grades. Elongation at break is 42% and the elastic modulus is 160 GPa (23.2 Msi).
Thermal6
Monel 401 is rated for continuous service to 425°C (797 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), better than 88% of nickel alloy grades. Thermal expansion is 14.2 µm/m·K (7.89 µin/in·°F).
Electrical3
Monel 401 conducts electricity at 3.6 % IACS, better than 92% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 77% of nickel alloy grades.
Sustainability4
Producing a kilogram of Monel 401 takes about 105 MJ of energy and emits 7.5 kg of CO₂ — less than 94% of nickel alloy grades. Typical recycled content is 30%.
Manufacturability8
Monel 401's machinability is poor (30/100, better than 90% of nickel alloy grades); weldability good (65/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Monel 401 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Monel 401
Is Monel 401 easy to machine?
Work-hardens rapidly — use sharp, positive-rake carbide, heavy positive feed, rigid setup, low-to-moderate speed and flood sulfur-free coolant; avoid dwelling.
Can Monel 401 be welded?
GTAW/GMAW with Monel-type Ni-Cu filler (ERNiCu-7); keep parts free of sulfur, lead and grease, use low heat input and no post-weld hardening treatment.
Can Monel 401 be formed, bent or molded?
Excellent cold formability in the annealed temper (deep drawing, coiling, stamping); interstage anneal at 760–870 °C followed by rapid cooling after heavy reductions.
Monel 401 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| NiNi + Co | 40 – 45 | 43 |
| Mn | ≤ 2.25 | 1.6 |
| Fe | ≤ 0.75 | 0.3 |
| C | ≤ 0.1 | 0.05 |
| Si | ≤ 0.25 | 0.1 |
| S | ≤ 0.02 | 0.01 |
| Cubalance, approx. 53–57 % | balance |
What surface finishes work on Monel 401?
Not anodizable; pickle or bright-anneal to remove oxide, then polish, or electroplate Ni/Ag/Au for solderable, low-contact-resistance surfaces.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Monel 401 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N04401
How much does Monel 401 cost?
Monel 401 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Monel 401 — frequently asked
What is Monel 401 used for?
Monel 401 is typically used for electrical resistors, thermostat components and corrosion-resistant springs. In short: controlled-resistivity Monel; corrosion-resistant spring material; high cold formability annealed.
What is the yield strength of Monel 401?
Monel 401 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 96% of nickel alloy grades. Strength varies by condition: see the 6 listed tempers.
Is Monel 401 easy to machine?
Not especially — machinability is rated poor (30/100, better than 90% of nickel alloy grades). Work-hardens rapidly — use sharp, positive-rake carbide, heavy positive feed, rigid setup, low-to-moderate speed and flood sulfur-free coolant; avoid dwelling.
Can Monel 401 be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW with Monel-type Ni-Cu filler (ERNiCu-7); keep parts free of sulfur, lead and grease, use low heat input and no post-weld hardening treatment.
What surface finishes work on Monel 401?
Not anodizable; pickle or bright-anneal to remove oxide, then polish, or electroplate Ni/Ag/Au for solderable, low-contact-resistance surfaces.
Can Monel 401 be formed, bent or molded?
Excellent cold formability in the annealed temper (deep drawing, coiling, stamping); interstage anneal at 760–870 °C followed by rapid cooling after heavy reductions.
What is the maximum service temperature of Monel 401?
Monel 401 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Monel 401-ANN and Monel 401-SPR?
ANN is the default condition — standard stocked condition: maximum ductility for stamping, drawing and coil winding, most stable resistivity. SPR: for coil and flat springs, contact fingers and resistance elements needing high elastic limit. Yield strength is 170 MPa in ANN versus 720 MPa in SPR.
How much does Monel 401 cost?
Monel 401 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Monel alloy 401 product data (Ni-Cu resistance alloy) — Special Metals Corporation (2005)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B: Corrosion — Materials — ASM International (2005)
- UNS N04401 designation (Metals & Alloys in the Unified Numbering System) — SAE/ASTM (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.