Nickel Alloy Monel K500 · precip hard
Nickel Alloy Monel K500-AT
Properties of the AT condition, compared with the other Monel K500 tempers.
Standard stocked high-strength condition for shafts, valve stems and fasteners with good ductility.
What is Monel K500-AT?
Monel K500-AT is Monel K500 in the AT condition — standard stocked high-strength condition for shafts, valve stems and fasteners with good ductility. Monel K500-AT has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 83% of nickel alloy grades. Elongation at break is 20% and the elastic modulus is 180 GPa (26.1 Msi). Monel K500-AT has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 61% of nickel alloy grades. It melts at 1,315°C (2,399 °F). O is the default condition FabDigit quotes; AT is available on request or by drawing note.
Advantages
- High electrical conductivity — 2.9 % IACS, better than 86% 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
- High strength — 790 MPa (115 ksi), better than 83% of nickel alloy grades
Limitations
- Low stiffness — 180 GPa (26.1 Msi), worse than 86% of nickel alloy grades
- Limited service temperature — 480°C (896 °F), worse than 81% of nickel alloy grades
- Limited ductility — 20%, worse than 77% of nickel alloy grades
- Limited formability — 20/100, worse than 77% of nickel alloy grades
Monel K500-AT properties
Typical room-temperature values for Monel K500-AT — 18 properties are specific to this condition; the rest are grade-level values shared by every Monel K500 temper. Each bar shows where the value sits among the nickel alloy grades in FabDigit's library — further right is higher.
Physical3
Monel K500-AT has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 61% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical15
Monel K500-AT has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 83% of nickel alloy grades. Elongation at break is 20% and the elastic modulus is 180 GPa (26.1 Msi).
Thermal6
Monel K500-AT 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-AT conducts electricity at 2.9 % IACS, better than 86% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 50% of nickel alloy grades.
Sustainability4
Producing a kilogram of Monel K500-AT takes about 150 MJ of energy and emits 12 kg of CO₂ — less than 66% of nickel alloy grades. Typical recycled content is 30%.
Manufacturability7
Monel K500-AT's machinability is poor (22/100, better than 63% of nickel alloy grades); weldability good (55/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Monel K500 tempers and conditions
Monel K500 is also supplied in 7 other conditions. The full side-by-side table is on the Monel K500 overview.
- ODefaultChoose for cold forming, deep drawing or machining prior to age hardening.310 MPa yield · 150 HB
- SpringSpring wire and strip needing maximum strength and resilience in seawater or sour service.1,100 MPa yield · 38 HRC
- CD+ATHighest-strength bar/wire condition for fasteners, studs and instrument parts up to ~1300 MPa.965 MPa yield · 35 HRC
- HF+ATHeavy-section age-hardened bar and forgings for pump/propeller shafting and downhole tools.850 MPa yield · 32 HRC
- ATStandard stocked high-strength condition for shafts, valve stems and fasteners with good ductility.790 MPa yield · 30 HRC
- Cold DrawnPrecision-size bar and wire with raised yield strength, used where age hardening is not required.585 MPa yield · 20 HRC
- HFLarge-section hot-worked bar/forgings supplied for subsequent machining and age hardening.550 MPa yield · 190 HB
- HWAs-hot-worked (hot-rolled, hot-forged or hot-finished) K-500 before precipitation ageing: moderate strength, high ductility and toughness.380 MPa yield · 160 HB
Working with Monel K500-AT
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.
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.
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) | — |
Monel K500-AT — frequently asked
What is Monel K500-AT used for?
Monel K500-AT 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-AT?
Monel K500-AT has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 83% of nickel alloy grades. Strength varies by condition: see the 8 listed tempers.
Is Monel K500-AT easy to machine?
Not especially — machinability is rated poor (22/100, better than 63% 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-AT be welded?
Yes — weldability is rated good (55/100). 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-AT?
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-AT 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-AT?
Monel K500-AT 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.
Can FabDigit make parts in Monel K500-AT?
Yes — Monel K500-AT 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.