Nickel Alloy Alloy 825
UNS N08825 · ASTM B424 · EN 2.4858 · BS NA16 · also Incoloy 825
Alloy 825 (N08825, 2.4858, Incoloy 825) is a titanium-stabilized Ni-Fe-Cr alloy with molybdenum and copper additions that resist sulfuric and phosphoric acid plus chloride-induced stress corrosion cracking.
Reference datasheet — Alloy 825 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
Alloy 825 tempers and conditions
Alloy 825 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution treated and aged | Choose when maximum resistance to intergranular attack after welding or service near sensitizing temperatures is required. | 300 | 670 | 44 | 158 HB | 1.5 % IACS |
ANNDefault Annealed | Standard stocked condition for plate, sheet, tube and bar; maximum ductility and corrosion resistance. | 310 | 690 | 45 | 150 HB | — |
Hot Finished | Economical condition for large-diameter bar, flanges and forgings where surface finish and tight tolerance are not critical. | 310 | 655 | 42 | 165 HB | — |
Cold drawn | Pick for higher strength, straightness and good surface on small-diameter bar, fasteners and instrumentation tubing. | 560 | 790 | 25 | 20 HRC | — |
Cold Worked Hard | Use where maximum strength and spring temper are needed and forming/welding is complete. | 760 | 950 | 12 | 28 HRC | 1.5 % IACS |
What is Alloy 825?
Alloy 825 (N08825, 2.4858, Incoloy 825) is a titanium-stabilized Ni-Fe-Cr alloy with molybdenum and copper additions that resist sulfuric and phosphoric acid plus chloride-induced stress corrosion cracking. It is a staple for chemical processing and oil & gas, supplied as plate, sheet, seamless tube, bar and forgings in annealed condition (310 MPa yield, 690 MPa tensile, 45 % elongation, ~150 HB). Service is limited to about 540 °C and machinability is poor (score 25) because the alloy work-hardens rapidly; welding and forming are straightforward. Alloy 20 is the lower-cost acid option, C-276 the step up for oxidizing chloride service. Alloy 825 has a density of 8.14 g/cm³ (0.294 lb/in³), lighter than 74% of nickel alloy grades. It melts at 1,370°C (2,498 °F). Alloy 825 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 196 GPa (28.4 Msi).
What is Alloy 825 used for?
- acid production equipment
- pickling tanks
- oil/gas tubulars
- pollution-control scrubbers
Advantages
- Low embodied carbon — 8.5 kg CO₂/kg, better than 92% of nickel alloy grades
- Forms and bends easily — 80/100, better than 91% of nickel alloy grades
- Readily welded — 85/100, better than 83% of nickel alloy grades
Limitations
- Limited service temperature — 540°C (1,004 °F), worse than 75% of nickel alloy grades
Alloy 825 properties
Typical room-temperature values for Alloy 825-ANN; bars are the position among nickel alloy grades.
Physical3
Alloy 825 has a density of 8.14 g/cm³ (0.294 lb/in³), lighter than 74% of nickel alloy grades. It melts at 1,370°C (2,498 °F).
Mechanical14
Alloy 825 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 196 GPa (28.4 Msi).
Thermal6
Alloy 825 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
Alloy 825 conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 67% of nickel alloy grades.
Sustainability4
Producing a kilogram of Alloy 825 takes about 115 MJ of energy and emits 8.5 kg of CO₂ — less than 91% of nickel alloy grades. Typical recycled content is 45%.
Manufacturability8
Alloy 825's machinability is poor (25/100, better than 76% of nickel alloy grades); weldability excellent (85/100); formability very good (80/100).
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. Alloy 825 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Alloy 825
Is Alloy 825 easy to machine?
Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed (20–35 m/min carbide) and copious sulfur-free coolant; never dwell in the cut.
Can Alloy 825 be welded?
Readily welded by GTAW/GMAW/SMAW with matching ERNiFeCr-1 (FM 65) or ENiCrMo-3 filler; keep heat input and interpass temperature low, no preheat, no post-weld heat treatment normally required thanks to Ti stabilization.
Can Alloy 825 be formed, bent or molded?
Excellent cold formability (deep drawing, spinning, tube bending) with ~40 % higher forming loads than 304; hot work 870–1180 °C and anneal at 940–1010 °C with rapid cool after heavy cold work.
Alloy 825 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 |
|---|---|---|
| Niplus Co in some specs | 38 – 46 | 42 |
| Cr | 19.5 – 23.5 | 21.5 |
| Mo | 2.5 – 3.5 | 3 |
| Cuaids sulfuric acid resistance | 1.5 – 3 | 2.2 |
| Tistabilizes against intergranular attack | 0.6 – 1.2 | 0.9 |
| C | ≤ 0.05 | 0.02 |
| Mn | ≤ 1 | 0.5 |
| Si | ≤ 0.5 | 0.25 |
| Al | ≤ 0.2 | 0.1 |
| S | ≤ 0.03 | 0 |
| Febalance, 22 % minimum per ASTM B424 | ≥ 22 (balance) |
What surface finishes work on Alloy 825?
Descale by grit blast plus HNO₃-HF pickling; passivate or electropolish for process-fluid cleanliness — anodizing is not applicable, and iron contamination from tooling must be removed to preserve pitting resistance.
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 Alloy 825 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08825
- ASTM
- B424
- EN / DIN / Werkstoff-Nr.
- 2.4858
- BS
- NA16
- Trade names
- Incoloy 825
- Similar grades
- NiCr21Mo
How much does Alloy 825 cost?
Alloy 825 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.
Alloy 825 — frequently asked
What is Alloy 825 used for?
Alloy 825 is typically used for acid production equipment, pickling tanks, oil/gas tubulars and pollution-control scrubbers. In short: acid-resistant Ni-Fe-Cr workhorse; strong chloride SCC resistance; weldable without PWHT.
What is the yield strength of Alloy 825?
Alloy 825 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 5 listed tempers.
Is Alloy 825 easy to machine?
Not especially — machinability is rated poor (25/100, better than 76% of nickel alloy grades). Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed (20–35 m/min carbide) and copious sulfur-free coolant; never dwell in the cut.
Can Alloy 825 be welded?
Yes — weldability is rated excellent (85/100). Readily welded by GTAW/GMAW/SMAW with matching ERNiFeCr-1 (FM 65) or ENiCrMo-3 filler; keep heat input and interpass temperature low, no preheat, no post-weld heat treatment normally required thanks to Ti stabilization.
What surface finishes work on Alloy 825?
Descale by grit blast plus HNO₃-HF pickling; passivate or electropolish for process-fluid cleanliness — anodizing is not applicable, and iron contamination from tooling must be removed to preserve pitting resistance.
Can Alloy 825 be formed, bent or molded?
Excellent cold formability (deep drawing, spinning, tube bending) with ~40 % higher forming loads than 304; hot work 870–1180 °C and anneal at 940–1010 °C with rapid cool after heavy cold work.
What is the maximum service temperature of Alloy 825?
Alloy 825 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 Alloy 825-ANN and Alloy 825 CW-H?
ANN is the default condition — standard stocked condition for plate, sheet, tube and bar; maximum ductility and corrosion resistance. CW-H: use where maximum strength and spring temper are needed and forming/welding is complete. Yield strength is 310 MPa in ANN versus 760 MPa in CW-H.
How much does Alloy 825 cost?
Alloy 825 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 B424 — Ni-Fe-Cr-Mo-Cu Alloy Plate, Sheet and Strip (UNS N08825) — ASTM International (2023)
- ASTM B425 — Ni-Fe-Cr-Mo-Cu Alloy Rod and Bar — ASTM International (2023)
- ASTM B163 / B423 — Seamless Tube and Pipe, UNS N08825 — ASTM International (2023)
- INCOLOY alloy 825 Technical Bulletin — Special Metals Corporation (2004)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys, Ni-Fe-Cr alloys — ASM International (1990)
- GB/T 15007 / NS1402 — SAC (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.