Nickel Alloy Inconel 625 · temper · default condition
Nickel Alloy Inconel 625-O
Properties of the O condition, compared with the other Inconel 625 tempers.
Standard stocked condition for sheet, plate, bar and pipe used below ~600 °C; best combination of strength, ductility and corrosion resistance.
What is Inconel 625-O?
Inconel 625-O is Inconel 625 in the O temper — standard stocked condition for sheet, plate, bar and pipe used below ~600 °C; best combination of strength, ductility and corrosion resistance. Inconel 625-O has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 72% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 207.5 GPa (30.1 Msi). Inconel 625-O has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 61% of nickel alloy grades. It melts at 1,290°C (2,354 °F).
Advantages
- Readily welded — 88/100, better than 92% of nickel alloy grades
- Good corrosion resistance — 90/100, better than 85% of nickel alloy grades
Limitations
- Poor heat conductor — 9.8 W/m·K (5.66 BTU/hr·ft·°F), worse than 92% of nickel alloy grades
Inconel 625-O properties
Typical room-temperature values for Inconel 625-O — 12 properties are specific to this condition; the rest are grade-level values shared by every Inconel 625 temper. Each bar shows where the value sits among the nickel alloy grades in FabDigit's library — further right is higher.
Physical3
Inconel 625-O has a density of 8.44 g/cm³ (0.305 lb/in³), heavier than 61% of nickel alloy grades. It melts at 1,290°C (2,354 °F).
Mechanical16
Inconel 625-O has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 72% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 207.5 GPa (30.1 Msi).
Thermal6
Inconel 625-O is rated for continuous service to 650°C (1,202 °F). It conducts heat at 9.8 W/m·K (5.66 BTU/hr·ft·°F), worse than 92% of nickel alloy grades. Thermal expansion is 12.8 µm/m·K (7.11 µin/in·°F).
Electrical3
Inconel 625-O conducts electricity at 1.3 % IACS, worse than 89% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 85% of nickel alloy grades.
Sustainability4
Producing a kilogram of Inconel 625-O takes about 225 MJ of energy and emits 14 kg of CO₂ — more than 88% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability8
Inconel 625-O's machinability is poor (18/100, worse than 62% of nickel alloy grades); weldability excellent (88/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Inconel 625 tempers and conditions
Inconel 625 is also supplied in 9 other conditions. The full side-by-side table is on the Inconel 625 overview.
- ODefaultStandard stocked condition for sheet, plate, bar and pipe used below ~600 °C; best combination of strength, ductility and corrosion resistance.490 MPa yield · 190 HB
- Cold DrawnChoose for high-strength wire, springs, fasteners and precision tube where cold-work strengthening replaces heat treatment.900 MPa yield · 32 HRC
- AgedPick when maximum room- and mid-temperature strength/hardness is needed (springs, fasteners, downhole tools); ductility and toughness drop.860 MPa yield · 35 HRC
- As PrintedBaseline for SLM/DMLS IN625 parts; fine cellular microstructure gives high yield strength but anisotropy and high residual stress.720 MPa yield · 30 HRC
- Stress RelievedUse to remove residual stress from cold work, welding or laser powder-bed printing while keeping most of the as-worked/as-printed strength.680 MPa yield · 30 HRC
- HIPFor additive or cast parts needing near-zero porosity and isotropic, fatigue-critical properties (aerospace, subsea).450 MPa yield · 175 HB
- Solution AnnealedChoose for service above ~600 °C where creep resistance and freedom from carbide/δ-phase embrittlement matter more than room-temperature strength.390 MPa yield · 165 HB
- Grade 2 Solution TreatedASTM B443/B444 Grade 2 material solution-treated at 1093–1204 °C for elevated-temperature service, giving lower strength but greater creep resistance and ductility than the mill-annealed Grade 1.330 MPa yield · 170 HB
Working with Inconel 625-O
Is Inconel 625 easy to machine?
Machine like a gummy austenitic superalloy: rigid setups, positive-rake carbide or ceramic tooling, 20–35 m/min with carbide, heavy constant feed to cut under the work-hardened layer, and flood high-pressure coolant.
Can Inconel 625 be welded?
Readily welded by GTAW/GMAW/PAW/laser with ERNiCrMo-3 filler, no preheat and normally no PWHT; keep interpass temperature low, use stringer beads and avoid 650–760 °C dwell to prevent sensitization and knife-line attack.
Can Inconel 625 be formed, bent or molded?
Cold forms well but needs ~2× the press capacity of 304 stainless and frequent intermediate anneals at 980–1040 °C; hot work 950–1200 °C, never in the 760–870 °C range for heavy reductions.
What surface finishes work on Inconel 625?
Pickle/descale in nitric-HF after annealing, then electropolish or mechanically polish; not anodizable — use passivation, glass-bead or electropolished finishes, and grit-blast only with alumina to avoid iron contamination.
Inconel 625 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 |
|---|---|---|
| Cr | 20 – 23 | 21.5 |
| Mo | 8 – 10 | 9 |
| NbNb+Ta combined | 3.15 – 4.15 | 3.65 |
| Fe | ≤ 5 | 3 |
| Coif determined | ≤ 1 | 0.2 |
| Al | ≤ 0.4 | 0.2 |
| Ti | ≤ 0.4 | 0.2 |
| Mn | ≤ 0.5 | 0.2 |
| Si | ≤ 0.5 | 0.2 |
| C | ≤ 0.1 | 0.05 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Nibalance, min 58 % per ASTM B443/UNS N06625 | ≥ 58 (balance) | — |
Inconel 625-O — frequently asked
What is Inconel 625-O used for?
Inconel 625-O is typically used for subsea piping and umbilical tubing, aerospace exhaust ducts and bellows, flue-gas desulfurization components, seawater heat exchangers, chemical process vessels and pipe spools and downhole safety valve components. In short: marine corrosion superalloy.
What is the yield strength of Inconel 625-O?
Inconel 625-O has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 72% of nickel alloy grades. Strength varies by condition: see the 10 listed tempers.
Is Inconel 625-O easy to machine?
Not especially — machinability is rated poor (18/100, worse than 62% of nickel alloy grades). Machine like a gummy austenitic superalloy: rigid setups, positive-rake carbide or ceramic tooling, 20–35 m/min with carbide, heavy constant feed to cut under the work-hardened layer, and flood high-pressure coolant.
Can Inconel 625-O be welded?
Yes — weldability is rated excellent (88/100). Readily welded by GTAW/GMAW/PAW/laser with ERNiCrMo-3 filler, no preheat and normally no PWHT; keep interpass temperature low, use stringer beads and avoid 650–760 °C dwell to prevent sensitization and knife-line attack.
What surface finishes work on Inconel 625-O?
Pickle/descale in nitric-HF after annealing, then electropolish or mechanically polish; not anodizable — use passivation, glass-bead or electropolished finishes, and grit-blast only with alumina to avoid iron contamination.
Can Inconel 625-O be formed, bent or molded?
Cold forms well but needs ~2× the press capacity of 304 stainless and frequent intermediate anneals at 980–1040 °C; hot work 950–1200 °C, never in the 760–870 °C range for heavy reductions.
What is the maximum service temperature of Inconel 625-O?
Inconel 625-O is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Inconel 625-O and Inconel 625 Aged?
O is the default condition — standard stocked condition for sheet, plate, bar and pipe used below ~600 °C; best combination of strength, ductility and corrosion resistance. Aged: pick when maximum room- and mid-temperature strength/hardness is needed (springs, fasteners, downhole tools); ductility and toughness drop. Yield strength is 490 MPa in O versus 860 MPa in Aged.
Can FabDigit make parts in Inconel 625-O?
Yes — Inconel 625-O is available for CNC machining, sheet metal and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B443 / B444 / B446 — Alloy N06625 plate, sheet, strip, pipe and bar — ASTM International (2019)
- GB/T 15007 / GB/T 15062 — (GH3625/NS3306 ) — SAC (2017)
- INCONEL alloy 625 Publication SMC-063 — Special Metals Corporation (PCC) (2013)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys (Ni-base superalloys) — ASM International (1990)
- MMPDS-2023 — Metallic Materials Properties Development and Standardization — Battelle/FAA (2023)
- EOS NickelAlloy IN625 material data sheet (LPBF) — EOS GmbH (2022)
- AWS A5.14 ERNiCrMo-3 filler metal specification — American Welding Society (2018)
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.