ASTM B564 Incoloy 825 (UNS N08825) Nickel Alloy Spring Seat
Incoloy 825 (UNS N08825) nickel alloy spring seats offer excellent corrosion, pitting and stress corrosion cracking resistance. They are suitable for high-pressure and corrosive-service valves used in oil & gas, chemical processing and offshore applications.
Key Features
- Resistant to acidic media, pitting and stress corrosion cracking.
- Suitable for supporting and positioning components in high-pressure valves.
- Maintains stable performance under elevated temperatures and demanding service conditions.
- Provides good dimensional accuracy and fit after precision machining.
- Suitable for corrosive environments in oil & gas, chemical processing and offshore engineering.
Typical Applications
- Used in valves handling high pressure, corrosive and acidic media.
- Used in valves and equipment exposed to acidic and corrosive media.
- Suitable for valve components used in seawater, salt spray and marine environments.
- Used in valves for refining, petrochemical processing and corrosive-fluid systems.
- Suitable for valve internals requiring high corrosion resistance and reliability.
Chemical Composition (wt%)
| Element |
Ni |
Cr |
Fe |
Mo |
Cu |
Ti |
C |
Mn |
Si |
Al |
S |
| Range |
38.0–46.0 |
19.5–23.5 |
≥22.0 |
2.5–3.5 |
1.5–3.0 |
0.6–1.2 |
≤0.05 |
≤1.0 |
≤0.50 |
≤0.20 |
≤0.03 |
Mechanical Properties (Solution Annealed + Water Quenched)
| Property |
Value |
| Tensile Strength (Rm) |
≥ 586 MPa (85 ksi) |
| Yield Strength (Rp0.2) |
≥ 241 MPa (35 ksi) |
| Elongation (A5) |
≥ 30 % |
| Density |
8.14 g/cm³ |
| Hardness |
≤ 200 HB |
| Modulus of Elasticity |
196 GPa |
| Max Service Temperature |
≤ 540°C(1000°F) |
Precautions
- Maintain strict dimensional tolerances for proper valve fit and operation.
- Avoid excessive cold working that may affect material performance.
- Control welding heat input when welding is required to prevent adverse microstructural changes.
- Evaluate temperature, pressure and stress carefully for elevated-temperature service.
- Maintain full material traceability and provide MTR and inspection records as required.
Quality Assurance
Incoloy 825 (UNS N08825) spring seats are forged per ASTM B564 for API 6A sour‑service valves, NACE MR0175 / ISO 15156‑3 compliant. Inspection scope covers PT, UT, tensile test, OES, PMI, hardness test and dimensional verification. Full material traceability shall be maintained; MTR, heat‑treatment records and NDT inspection reports shall be provided upon request.
Contact our sales team today for a competitive quote, technical datasheet, or to discuss your custom forging requirements.

