Nickel Alloy 925
UNS N09925
Alloy 925 (UNS N09925) is an age-hardenable Ni-Fe-Cr-Mo-Cu-Ti alloy that combines Alloy 825-level corrosion resistance with higher strength from Ti/Al precipitation hardening.
Reference datasheet — 925 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 STA condition
925 tempers and conditions
925 is supplied in 7 conditions, soft to hard. STA is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed (≈1010–1040 °C, rapid cool), not aged | Softest condition, supplied for further forming, deep drawing, or customer-performed aging. | 380 | 760 | 45 | 185 HB | — |
Cold drawn | Cold-drawn bar, tube or wire supplied for tight tolerance and moderate strength before customer aging. | 690 | 900 | 25 | 24 HRC | 1.5 % IACS |
API 6ACRA 110 ksi | Sour-service wellhead/valve grade where NACE hardness limits and impact toughness dominate over peak strength. | 810 | 1,100 | 24 | 32 HRC | 1.5 % IACS |
STADefault Solution treated and aged | Standard delivery condition for oilfield bar, forgings and fasteners needing ≥760 MPa yield with sour-service hardness control. | 830 | 1,210 | 25 | 33 HRC | — |
API 6ACRA 120 ksi | Most common oilfield strength class for 925 bar/forgings in hangers, mandrels and stems. | 880 | 1,170 | 22 | 34 HRC | 1.5 % IACS |
API 6ACRA 140 ksi | High-strength class for smaller cross-sections and fasteners; check NACE hardness/environment limits before sour service. | 1,010 | 1,240 | 19 | 37 HRC | 1.5 % IACS |
Cold worked then aged | Highest-strength condition for spring wire and studs; verify hardness stays within NACE limits for sour environments. | 1,050 | 1,330 | 15 | 40 HRC | 1.5 % IACS |
What is 925?
Alloy 925 (UNS N09925) is an age-hardenable Ni-Fe-Cr-Mo-Cu-Ti alloy that combines Alloy 825-level corrosion resistance with higher strength from Ti/Al precipitation hardening. It is specified for oil and gas hardware in API-110, API-120 and API-140 strength classes, supplied as bar, forgings and cold-drawn stock; typical aged properties are 830 MPa yield, 1210 MPa tensile, 25 % elongation and 320 HB (33 HRC). The trade-offs are a 540 °C service limit, poor machinability (score 18), very low formability (20) and welding that requires full re-solution and re-age. Alloy 718 is the higher-strength alternative; Alloy 825 is the lower-cost, non-hardenable option. 925 has a density of 8.08 g/cm³ (0.292 lb/in³), lighter than 81% of nickel alloy grades. It melts at 1,315°C (2,399 °F). 925 has a yield strength of 830 MPa (120 ksi) and a tensile strength of 1,210 MPa (175 ksi) — stronger than 88% of nickel alloy grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
What is 925 used for?
- oil & gas downhole tooling
- fasteners in sour service
- corrosion-resistant high-strength components
Advantages
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 91% of nickel alloy grades
- High strength — 830 MPa (120 ksi), better than 88% of nickel alloy grades
Limitations
- 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
925 properties
Typical room-temperature values for 925-STA; bars are the position among nickel alloy grades.
Physical3
925 has a density of 8.08 g/cm³ (0.292 lb/in³), lighter than 81% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical15
925 has a yield strength of 830 MPa (120 ksi) and a tensile strength of 1,210 MPa (175 ksi) — stronger than 88% of nickel alloy grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
925 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 13 µm/m·K (7.22 µin/in·°F).
Electrical3
925 conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (84/100), better than 70% of nickel alloy grades.
Sustainability4
Producing a kilogram of 925 takes about 150 MJ of energy and emits 12.5 kg of CO₂ — less than 68% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability6
925's machinability is poor (18/100, worse than 61% of nickel alloy grades); weldability good (55/100); 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. 925 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 925
Is 925 easy to machine?
Machine preferably in the aged condition with rigid setups, positive-rake carbide, heavy depth of cut, low surface speed (20–35 m/min) and flood coolant to avoid work hardening and glazing.
Can 925 be welded?
GTAW/GMAW with ERNiFeCr-1 (alloy 725/625-type) filler, low heat input, no preheat; re-solution + re-age after welding to restore strength and avoid strain-age cracking in the HAZ.
Can 925 be formed, bent or molded?
Cold form only in the solution-annealed condition (high work-hardening rate, high forming loads); hot work 1010–1180 °C and finish above 950 °C, then solution treat before aging.
925 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 | 42 – 46 | 44 |
| Cr | 19.5 – 23.5 | 21 |
| Mo | 2.5 – 3.5 | 3 |
| Cu | 1.5 – 3 | 2.2 |
| Timain γ′ former | 1.9 – 2.4 | 2.1 |
| Al | 0.1 – 0.5 | 0.3 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 0.5 | 0.2 |
| C | ≤ 0.03 | 0.01 |
| S≤0.010 typical for oilfield melts | ≤ 0.03 | 0 |
| P | ≤ 0.03 | 0.01 |
| Febalance, 22 % min | ≥ 22 (balance) |
What surface finishes work on 925?
Passivation or pickling after descaling restores the Cr-rich film; grinds and polishes well to mirror finish; no anodizing — plating rarely needed as the alloy is inherently corrosion resistant.
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 925 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N09925
How much does 925 cost?
925 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.
925 — frequently asked
What is 925 used for?
925 is typically used for oil & gas downhole tooling, fasteners in sour service and corrosion-resistant high-strength components. In short: sour-service high-strength CRA; age-hardened Alloy 825; API-140 strength classes.
What is the yield strength of 925?
925 has a typical yield strength of 830 MPa (120 ksi) and a tensile strength of 1,210 MPa (175 ksi) — stronger than 88% of nickel alloy grades. Strength varies by condition: see the 7 listed tempers.
Is 925 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 61% of nickel alloy grades). Machine preferably in the aged condition with rigid setups, positive-rake carbide, heavy depth of cut, low surface speed (20–35 m/min) and flood coolant to avoid work hardening and glazing.
Can 925 be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW with ERNiFeCr-1 (alloy 725/625-type) filler, low heat input, no preheat; re-solution + re-age after welding to restore strength and avoid strain-age cracking in the HAZ.
What surface finishes work on 925?
Passivation or pickling after descaling restores the Cr-rich film; grinds and polishes well to mirror finish; no anodizing — plating rarely needed as the alloy is inherently corrosion resistant.
Can 925 be formed, bent or molded?
Cold form only in the solution-annealed condition (high work-hardening rate, high forming loads); hot work 1010–1180 °C and finish above 950 °C, then solution treat before aging.
What is the maximum service temperature of 925?
925 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 925-STA and 925-SA?
STA is the default condition — standard delivery condition for oilfield bar, forgings and fasteners needing ≥760 MPa yield with sour-service hardness control. SA: softest condition, supplied for further forming, deep drawing, or customer-performed aging. Yield strength is 830 MPa in STA versus 380 MPa in SA.
How much does 925 cost?
925 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
- INCOLOY alloy 925 technical bulletin — Special Metals Corporation (2004)
- API 6ACRA — Age-hardenable nickel-based alloys for oil and gas drilling and production equipment — API (2020)
- ASTM B805 — Precipitation-hardening nickel alloy (UNS N09925) bar and forgings — ASTM International (2018)
- NACE MR0175 / ISO 15156-3 — Cracking-resistant CRAs for H2S service — NACE/ISO (2020)
- 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.