Nickel Alloy Monel R-405
UNS N04405 · ASTM B164
Monel R-405 (N04405, ASTM B164) is the sulphur-bearing free-machining version of the Ni-Cu alloy Monel 400, formulated for high-speed screw-machine work while keeping comparable corrosion resistance (score 78) up to 480 °C.
Reference datasheet — Monel R-405 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 CD condition
Monel R-405 tempers and conditions
Monel R-405 is supplied in 4 conditions, soft to hard. CD is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick when maximum ductility, formability or lowest residual stress is needed, or for parts that will be cold-headed/upset before machining. | 220 | 520 | 40 | 120 HB | — |
Hot Finished | Pick for larger diameters and forged/hot-rolled sections where cold-drawn sizes are unavailable; intermediate strength with generous ductility. | 290 | 550 | 35 | 140 HB | — |
CDDefault Cold drawn | Default stock condition: straight, close-tolerance bar with higher strength and good chip breaking for automatic lathes. | 450 | 620 | 22 | 165 HB | — |
Stress relieved | Pick for slender turned parts and valve stems where distortion after machining and residual-stress corrosion cracking must be minimized while keeping high strength. | 520 | 655 | 18 | 180 HB | — |
What is Monel R-405?
Monel R-405 (N04405, ASTM B164) is the sulphur-bearing free-machining version of the Ni-Cu alloy Monel 400, formulated for high-speed screw-machine work while keeping comparable corrosion resistance (score 78) up to 480 °C. It is supplied mainly as annealed, cold-drawn, hot-finished and stress-relieved round bar for turned parts, with a machinability score of 50 — well above standard Monel. The sulphide stringers that break chips also rule out reliable welding, restrict hot working and limit polished surface quality. Use Monel 400 or K-500 where welded or forged parts are required. Monel R-405 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 82% of nickel alloy grades. It melts at 1,300°C (2,372 °F). Monel R-405 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 66% of nickel alloy grades. Elongation at break is 22% and the elastic modulus is 179 GPa (26 Msi).
What is Monel R-405 used for?
- screw-machine parts
- valve stems
- fittings
- precision turned components
Advantages
- Easy to machine — 50/100, better than 99% of nickel alloy grades
- Conducts heat well — 21.8 W/m·K (12.6 BTU/hr·ft·°F), better than 90% of nickel alloy grades
- High electrical conductivity — 3.2 % IACS, better than 89% of nickel alloy grades
- Low embodied carbon — 11 kg CO₂/kg, better than 85% of nickel alloy grades
Limitations
- Low stiffness — 179 GPa (26 Msi), worse than 88% of nickel alloy grades
- Difficult to weld — 20/100, worse than 84% of nickel alloy grades
- Hard to polish — 60/100, worse than 84% of nickel alloy grades
- Limited service temperature — 480°C (896 °F), worse than 82% of nickel alloy grades
Monel R-405 properties
Typical room-temperature values for Monel R-405-CD; bars are the position among nickel alloy grades.
Physical3
Monel R-405 has a density of 8.83 g/cm³ (0.319 lb/in³), heavier than 82% of nickel alloy grades. It melts at 1,300°C (2,372 °F).
Mechanical13
Monel R-405 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 66% of nickel alloy grades. Elongation at break is 22% and the elastic modulus is 179 GPa (26 Msi).
Thermal6
Monel R-405 is rated for continuous service to 480°C (896 °F). It conducts heat at 21.8 W/m·K (12.6 BTU/hr·ft·°F), better than 90% of nickel alloy grades. Thermal expansion is 13.9 µm/m·K (7.72 µin/in·°F).
Electrical3
Monel R-405 conducts electricity at 3.2 % IACS, better than 89% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 51% of nickel alloy grades.
Sustainability4
Producing a kilogram of Monel R-405 takes about 145 MJ of energy and emits 11 kg of CO₂ — less than 77% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability8
Monel R-405's machinability is fair (50/100, better than 99% of nickel alloy grades); weldability poor (20/100); formability fair (45/100).
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 R-405 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Monel R-405
Is Monel R-405 easy to machine?
The best-machining Monel: run rigid setups with positive-rake carbide, heavy feeds and flood coolant; chips break well but the alloy still work-hardens, so never dwell or rub.
Can Monel R-405 be welded?
Not recommended for welded joints — sulfur promotes hot cracking; use Monel 400/K-500 where welding is required, or mechanically join R-405 parts.
Can Monel R-405 be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot working is restricted (1040–1180 °C) because sulfur causes hot shortness.
Monel R-405 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 plus Co per ASTM B164 | ≥ 63 | 66 |
| Fe | ≤ 2.5 | 1.5 |
| Mn | ≤ 2 | 1 |
| Sintentional free-machining addition | 0.03 – 0.06 | 0.04 |
| C | ≤ 0.3 | 0.15 |
| Si | ≤ 0.5 | 0.2 |
| Cubalance in most producer listings | ≥ 28 (balance) |
What surface finishes work on Monel R-405?
Cannot be anodized; typical finishes are passivation, mechanical polish (sulfide stringers limit mirror quality), electroless nickel or silver/chrome plating.
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 R-405 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N04405
- ASTM
- B164
- Also called
- Monel 400
How much does Monel R-405 cost?
Monel R-405 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 R-405 — frequently asked
What is Monel R-405 used for?
Monel R-405 is typically used for screw-machine parts, valve stems, fittings and precision turned components. In short: best-machining Monel grade; screw-machine free-cutting bar; monel 400 corrosion resistance.
What is the yield strength of Monel R-405?
Monel R-405 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 66% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is Monel R-405 easy to machine?
Reasonably — machinability is rated fair (50/100, better than 99% of nickel alloy grades). The best-machining Monel: run rigid setups with positive-rake carbide, heavy feeds and flood coolant; chips break well but the alloy still work-hardens, so never dwell or rub.
Can Monel R-405 be welded?
Not readily — weldability is rated poor (20/100). Not recommended for welded joints — sulfur promotes hot cracking; use Monel 400/K-500 where welding is required, or mechanically join R-405 parts.
What surface finishes work on Monel R-405?
Cannot be anodized; typical finishes are passivation, mechanical polish (sulfide stringers limit mirror quality), electroless nickel or silver/chrome plating.
Can Monel R-405 be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot working is restricted (1040–1180 °C) because sulfur causes hot shortness.
What is the maximum service temperature of Monel R-405?
Monel R-405 is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Monel R-405-CD and Monel R-405-ANN?
CD is the default condition — default stock condition: straight, close-tolerance bar with higher strength and good chip breaking for automatic lathes. ANN: pick when maximum ductility, formability or lowest residual stress is needed, or for parts that will be cold-headed/upset before machining. Yield strength is 450 MPa in CD versus 220 MPa in ANN.
How much does Monel R-405 cost?
Monel R-405 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
- ASTM B164 — Nickel-Copper Alloy Rod, Bar and Wire — ASTM International (2020)
- MONEL alloy R-405 technical bulletin — Special Metals Corporation (2005)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
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.