Nickel Alloy CU5MCuC
UNS N08826, N08825 · ASTM A494 CU5MCuC
CU5MCuC (N08826, ASTM A494) is the cast counterpart of wrought Alloy 825, a Ni-Fe-Cr alloy with molybdenum and copper additions for resistance to sulfuric and phosphoric acid.
Reference datasheet — CU5MCuC 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 SA condition
CU5MCuC tempers and conditions
CU5MCuC is supplied in 4 conditions, soft to hard. SA 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 |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard supply condition for ASTM A494 CU5MCuC castings — maximum corrosion resistance and ductility. | 235 | 490 | 40 | 160 HB | — |
hot isostatically pressed then solution annealed | For pressure-containing or fatigue-loaded castings where shrinkage porosity must be closed. | 245 | 520 | 45 | 160 HB | 1.5 % IACS |
Spheroidize annealed | Only for non-critical or mildly corrosive service — interdendritic carbides/segregation reduce intergranular corrosion resistance. | 250 | 470 | 25 | 170 HB | 1.5 % IACS |
solution annealed plus stabilization anneal (≈930–980 °C) | Choose when the casting will see 425–650 °C service or heavy weld repair and maximum intergranular-corrosion immunity is required. | 250 | 500 | 35 | 165 HB | 1.5 % IACS |
What is CU5MCuC?
CU5MCuC (N08826, ASTM A494) is the cast counterpart of wrought Alloy 825, a Ni-Fe-Cr alloy with molybdenum and copper additions for resistance to sulfuric and phosphoric acid. Solution-annealed castings give 235 MPa yield, 490 MPa tensile, 40 % elongation and 160 HB (85 HRB), with a corrosion resistance score of 85 and a weldability score of 72, the easiest to repair-weld in this cast nickel group. Maximum service temperature is 540 °C and machinability scores 28. Where hydrochloric acid or mixed oxidising-reducing acids are involved, step up to CW6M or CW2M. CU5MCuC has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 80% of nickel alloy grades. It melts at 1,370°C (2,498 °F). CU5MCuC has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Elongation at break is 40% and the elastic modulus is 193 GPa (28 Msi).
What is CU5MCuC used for?
- pump and valve bodies
- chemical processing pumps
- sulfuric acid handling equipment
Advantages
- Low embodied carbon — 6.5 kg CO₂/kg, better than 99% of nickel alloy grades
Limitations
- Low strength — 235 MPa (34.1 ksi), worse than 91% of nickel alloy grades
- Hard to polish — 60/100, worse than 84% of nickel alloy grades
- Limited service temperature — 540°C (1,004 °F), worse than 75% of nickel alloy grades
- Limited formability — 20/100, worse than 75% of nickel alloy grades
CU5MCuC properties
Typical room-temperature values for CU5MCuC-SA; bars are the position among nickel alloy grades.
Physical3
CU5MCuC has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 80% of nickel alloy grades. It melts at 1,370°C (2,498 °F).
Mechanical12
CU5MCuC has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Elongation at break is 40% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
CU5MCuC is rated for continuous service to 540°C (1,004 °F). It conducts heat at 11.1 W/m·K (6.41 BTU/hr·ft·°F), worse than 54% of nickel alloy grades. Thermal expansion is 14 µm/m·K (7.78 µin/in·°F).
Electrical3
CU5MCuC conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 74% of nickel alloy grades.
Sustainability4
Producing a kilogram of CU5MCuC takes about 95 MJ of energy and emits 6.5 kg of CO₂ — less than 97% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability8
CU5MCuC's machinability is poor (28/100, better than 82% of nickel alloy grades); weldability very good (72/100); formability poor (20/100).
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. CU5MCuC is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CU5MCuC
Is CU5MCuC easy to machine?
Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy depth of cut, low speed (≈20–35 m/min) and flood coolant; never dwell in the cut.
Can CU5MCuC be welded?
Readily welded GTAW/SMAW with ERNiFeCr-1 (Alloy 65) or ENiCrMo-3 filler; low heat input, no preheat, interpass <150 °C, solution or stabilization anneal after major weld repair.
Can CU5MCuC be formed, bent or molded?
Sand or investment cast; long freezing range demands generous risering and chills, and pouring under argon/vacuum control to limit Ti loss and dross.
CU5MCuC 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 |
|---|---|---|
| C | ≤ 0.05 | 0.03 |
| Mn | ≤ 1 | 0.7 |
| Si | ≤ 1 | 0.7 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Ni | 38 – 44 | 41 |
| Cr | 19.5 – 23.5 | 21.5 |
| Mo | 2.5 – 3.5 | 3 |
| Cuimproves sulfuric acid resistance | 1.5 – 3.5 | 2.2 |
| Ticarbide stabilizer against sensitization | 0.6 – 1.2 | 0.9 |
| Feremainder, ≈28–32 % | balance |
What surface finishes work on CU5MCuC?
Grit-blast and pickle (HNO₃-HF) to remove casting scale, then passivate or electropolish; not anodizable, plating is rarely needed.
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 CU5MCuC in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08826N08825
- ASTM
- A494 CU5MCuC
How much does CU5MCuC cost?
CU5MCuC 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.
CU5MCuC — frequently asked
What is CU5MCuC used for?
CU5MCuC is typically used for pump and valve bodies, chemical processing pumps and sulfuric acid handling equipment. In short: cast Alloy 825; sulfuric acid workhorse; most weldable cast nickel grade.
What is the yield strength of CU5MCuC?
CU5MCuC has a typical yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is CU5MCuC easy to machine?
Not especially — machinability is rated poor (28/100, better than 82% of nickel alloy grades). Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy depth of cut, low speed (≈20–35 m/min) and flood coolant; never dwell in the cut.
Can CU5MCuC be welded?
Yes — weldability is rated very good (72/100). Readily welded GTAW/SMAW with ERNiFeCr-1 (Alloy 65) or ENiCrMo-3 filler; low heat input, no preheat, interpass <150 °C, solution or stabilization anneal after major weld repair.
What surface finishes work on CU5MCuC?
Grit-blast and pickle (HNO₃-HF) to remove casting scale, then passivate or electropolish; not anodizable, plating is rarely needed.
Can CU5MCuC be formed, bent or molded?
Sand or investment cast; long freezing range demands generous risering and chills, and pouring under argon/vacuum control to limit Ti loss and dross.
What is the maximum service temperature of CU5MCuC?
CU5MCuC is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CU5MCuC-SA and CU5MCuC-AC?
SA is the default condition — standard supply condition for ASTM A494 CU5MCuC castings — maximum corrosion resistance and ductility. AC: only for non-critical or mildly corrosive service — interdendritic carbides/segregation reduce intergranular corrosion resistance. Yield strength is 235 MPa in SA versus 250 MPa in AC.
How much does CU5MCuC cost?
CU5MCuC 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 A494/A494M — Castings, Nickel and Nickel Alloy — ASTM International (2023)
- INCOLOY alloy 825 technical bulletin — Special Metals Corporation (2004)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (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.