Nickel Alloy Monel K500
UNS N05500 · ASTM B865 · EN 2.4375, NiCu30Al · BS NA18
Precipitation-hardenable version of Monel 400 with added Al/Ti, giving roughly double the strength while retaining the base alloy's corrosion resistance; used for shafts and fasteners in seawater service.
Values for the O condition
Monel K500 tempers and conditions
Monel K500 is supplied in 8 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Choose for cold forming, deep drawing or machining prior to age hardening. | 310 | 690 | 45 | 150 HB | 2.8 % IACS |
Hot Worked | As-hot-worked (hot-rolled, hot-forged or hot-finished) K-500 before precipitation ageing: moderate strength, high ductility and toughness. | 380 | 690 | 35 | 160 HB | 2.8 % IACS |
Hot-finished | Large-section hot-worked bar/forgings supplied for subsequent machining and age hardening. | 550 | 830 | 30 | 190 HB | — |
cold-drawn / stress-equalized, not aged | Precision-size bar and wire with raised yield strength, used where age hardening is not required. | 585 | 800 | 22 | 20 HRC | 2.8 % IACS |
Annealed and age hardened | Standard stocked high-strength condition for shafts, valve stems and fasteners with good ductility. | 790 | 1,100 | 20 | 30 HRC | 2.9 % IACS |
Hot-finished and age hardened | Heavy-section age-hardened bar and forgings for pump/propeller shafting and downhole tools. | 850 | 1,140 | 20 | 32 HRC | — |
Cold drawn and age hardened | Highest-strength bar/wire condition for fasteners, studs and instrument parts up to ~1300 MPa. | 965 | 1,240 | 17 | 35 HRC | — |
Spring hard | Spring wire and strip needing maximum strength and resilience in seawater or sour service. | 1,100 | 1,350 | 12 | 38 HRC | 2.8 % IACS |
What is Monel K500?
Precipitation-hardenable version of Monel 400 with added Al/Ti, giving roughly double the strength while retaining the base alloy's corrosion resistance; used for shafts and fasteners in seawater service. Monel K500 has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 60% of nickel alloy grades. It melts at 1,315°C (2,399 °F). Monel K500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 74% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 179 GPa (26 Msi).
What is Monel K500 used for?
- Marine pump and propeller shafts
- Seawater pump impellers
- Valve stems and shafting
- Springs and retaining rings
- Offshore fasteners and studs
- Downhole tool components
- Instrument housings for seawater service
Advantages
- High electrical conductivity — 2.8 % IACS, better than 85% of nickel alloy grades
- Conducts heat well — 17.5 W/m·K (10.1 BTU/hr·ft·°F), better than 84% of nickel alloy grades
Limitations
- Low stiffness — 179 GPa (26 Msi), worse than 88% of nickel alloy grades
- Limited service temperature — 480°C (896 °F), worse than 82% of nickel alloy grades
Monel K500 properties
Typical room-temperature values for Monel K500-O; bars are the position among nickel alloy grades.
Physical3
Monel K500 has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 60% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical15
Monel K500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 74% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 179 GPa (26 Msi).
Thermal6
Monel K500 is rated for continuous service to 480°C (896 °F). It conducts heat at 17.5 W/m·K (10.1 BTU/hr·ft·°F), better than 84% of nickel alloy grades. Thermal expansion is 13.7 µm/m·K (7.61 µin/in·°F).
Electrical3
Monel K500 conducts electricity at 2.8 % IACS, better than 85% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 61% of nickel alloy grades.
Sustainability4
Producing a kilogram of Monel K500 takes about 150 MJ of energy and emits 12 kg of CO₂ — less than 68% of nickel alloy grades. Typical recycled content is 30%.
Manufacturability7
Monel K500's machinability is poor (18/100, worse than 61% of nickel alloy grades); weldability good (65/100); formability very good (70/100).
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 K500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Monel K500
Is Monel K500 easy to machine?
Machine like a high-strength Ni alloy: rigid setup, positive rake carbide, low speed (15–30 m/min) with heavy constant feed, flood coolant; the age-hardened state cuts more cleanly than the gummy annealed state and finish machining is normally done after aging.
Can Monel K500 be welded?
Weldable by GTAW/GMAW with Monel 60/64/67 (ERNiCu-7) filler using low heat input, no preheat and clean surfaces; joints in aged material lose strength in the HAZ, so re-solution + re-age (or accept annealed-level properties) for full-strength welds.
Can Monel K500 be formed, bent or molded?
Cold form, spin or draw only in the annealed condition — work hardening is rapid and springback high; hot work at 870–1175 °C, then anneal ~980 °C and age 580–600 °C for 8–16 h with slow cool.
Manufacturability
The process limits FabDigit's quote engine applies to Monel K500. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair18 / 100 |
|---|---|
| ISO material group | S.1 |
| Cutting speed (rough / finish) | 40 / 55 m/min |
| Minimum wall | 1.5 mm |
| Minimum internal radius | 2 mm |
| Drill depth limit | 3× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better70 / 100 |
|---|---|
| Weldability | Better65 / 100 |
| Bendable | Yes |
Monel K500 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 |
|---|---|---|
| Cu | 27 – 33 | 30 |
| Alγ' (Ni₃(Al,Ti)) former | 2.3 – 3.15 | 2.7 |
| Ti | 0.35 – 0.85 | 0.6 |
| Fe | ≤ 2 | 1 |
| Mn | ≤ 1.5 | 0.7 |
| Si | ≤ 0.5 | 0.15 |
| C | ≤ 0.25 | 0.13 |
| S | ≤ 0.01 | 0.01 |
| Nibalance, 63 % min per ASTM B865 | ≥ 63 (balance) |
What surface finishes work on Monel K500?
No anodizing; pickle/passivate to remove aging oxide, then grind, polish or electropolish for a bright marine finish; electroless nickel or chrome plating is possible but rarely needed, and shot peening is common on shafting for fatigue life.
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).
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Monel K500 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N05500
- ASTM
- B865
- EN / DIN / Werkstoff-Nr.
- 2.4375NiCu30Al
- BS
- NA18
How much does Monel K500 cost?
Monel K500 is a premium-cost nickel alloy ($$$), pricier than about 57% 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 K500 — frequently asked
What is Monel K500 used for?
Monel K500 is typically used for marine pump and propeller shafts, seawater pump impellers, valve stems and shafting, springs and retaining rings, offshore fasteners and studs and downhole tool components. In short: age-hardened seawater alloy.
What is the yield strength of Monel K500?
Monel K500 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 74% of nickel alloy grades. Strength varies by condition: see the 8 listed tempers.
Is Monel K500 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 61% of nickel alloy grades). Machine like a high-strength Ni alloy: rigid setup, positive rake carbide, low speed (15–30 m/min) with heavy constant feed, flood coolant; the age-hardened state cuts more cleanly than the gummy annealed state and finish machining is normally done after aging.
Can Monel K500 be welded?
Yes — weldability is rated good (65/100). Weldable by GTAW/GMAW with Monel 60/64/67 (ERNiCu-7) filler using low heat input, no preheat and clean surfaces; joints in aged material lose strength in the HAZ, so re-solution + re-age (or accept annealed-level properties) for full-strength welds.
What surface finishes work on Monel K500?
No anodizing; pickle/passivate to remove aging oxide, then grind, polish or electropolish for a bright marine finish; electroless nickel or chrome plating is possible but rarely needed, and shot peening is common on shafting for fatigue life.
Can Monel K500 be formed, bent or molded?
Cold form, spin or draw only in the annealed condition — work hardening is rapid and springback high; hot work at 870–1175 °C, then anneal ~980 °C and age 580–600 °C for 8–16 h with slow cool.
What is the maximum service temperature of Monel K500?
Monel K500 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 K500-O and Monel K500 Spring?
O is the default condition — choose for cold forming, deep drawing or machining prior to age hardening. Spring: spring wire and strip needing maximum strength and resilience in seawater or sour service. Yield strength is 310 MPa in O versus 1,100 MPa in Spring.
How much does Monel K500 cost?
Monel K500 is a premium-cost nickel alloy ($$$), pricier than about 57% 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.
Can FabDigit make parts in Monel K500?
Yes — Monel K500 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- MONEL alloy K-500 Publication SMC-062 — Special Metals Corporation (2004)
- ASTM B865 — Nickel-Copper-Aluminum Alloy (UNS N05500) Rod, Bar, Wire and Forgings — ASTM International (2018)
- ASTM F467/F468 — Nonferrous Nuts and Bolts for General Use — ASTM International (2019)
- QQ-N-286 — Nickel-Copper-Aluminum Alloy, Wrought — US Federal Specification (2000)
- 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)
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.