Alloy 625 is a nickel alloy with at least 58% nickel, 20–23% chromium, 8–10% molybdenum and 3.15–4.15% niobium. The molybdenum and niobium strengthen the alloy without a hardening treatment, so it keeps its strength and resists corrosion from cryogenic temperatures to about 980 °C. In the annealed condition (ASTM B446 Grade 1) it delivers 827 MPa minimum tensile strength, 414 MPa minimum yield and 30% minimum elongation. Engineers choose it for subsea and offshore components, chemical process equipment, aerospace ducting, flare tips and nuclear parts.
Alloy 625 is a special alloy, so we act as your sourcing partner: our metallurgists and mill network find the material, check it against your specification and deliver it across India and to partner markets abroad. We supply it as round bars in Ø 29–500 mm and square bars in 40–480 mm from our high-alloy range, and as rolled round bars in Ø 16–500 mm. Delivery condition is annealed, solution annealed or hot rolled. Send us your size, condition and quantity and we quote by quantity and size.
EQUIVALENT GRADES
Alloy 625 / UNS N06625 Equivalents
Direct means the same grade under another name. Close means the same alloy concept with slightly different limits, commonly substituted. Approximate means similar use with real differences: check with us before substituting.
| Standard | Designation | Match |
|---|---|---|
| EN | NiCr22Mo9Nb (2.4856) | Direct |
| DIN W.Nr. | 2.4856 | Direct |
| ASTM | B446 Grade 1 | Direct |
| ASTM | B446 | Direct |
| UNS | N06625 | Direct |
| JIS | NCF625 | Direct |
| GB | NS336 | Close |
| Trade name | Inconel® 625 | Direct |
Alloy 625 / UNS N06625 Chemical Composition
Per ASTM B446 / Special Metals datasheet (Alloy 625)
| Element | Range, wt % | Range chart |
|---|---|---|
| Ni | ≥ 58 | |
| Cr | 20 – 23 | |
| Mo | 8 – 10 | |
| Nb | 3.15 – 4.15 | |
| Fe | ≤ 5 | |
| C | ≤ 0.1 | |
| Mn | ≤ 0.5 | |
| Si | ≤ 0.5 | |
| P | ≤ 0.015 | |
| S | ≤ 0.015 | |
| Al | ≤ 0.4 | |
| Ti | ≤ 0.4 | |
| Co | ≤ 1 |
Alloy 625 / UNS N06625 and Its Equivalents: Chemical Composition
Equivalent grades are written to different standards, so their limits differ slightly. Use the column for the standard on your drawing or purchase order.
| Element | Alloy 625 UNS N06625 / ASTM B446 | NiCr22Mo9Nb (2.4856) EN 10095 / W.Nr. |
|---|---|---|
| C % | ≤ 0.10 | 0.03–0.10 |
| Si % | ≤ 0.50 | ≤ 0.50 |
| Mn % | ≤ 0.50 | ≤ 0.50 |
| P % | ≤ 0.015 | ≤ 0.015 |
| S % | ≤ 0.015 | ≤ 0.015 |
| Cr % | 20.00–23.00 | 20.00–23.00 |
| Mo % | 8.00–10.00 | 8.00–10.00 |
| Ni % | ≥ 58.00 | ≥ 58.00 |
| Co % | ≤ 1.00 | ≤ 1.00 |
| Al % | ≤ 0.40 | ≤ 0.40 |
| Ti % | ≤ 0.40 | ≤ 0.40 |
| Nb % | 3.15–4.15 | 3.15–4.15 |
| Fe % | ≤ 5.00 | ≤ 5.00 |
Alloy 625 / UNS N06625 Mechanical Properties
| Condition | Tensile, MPa | Yield min, MPa | Elongation min, % | Hardness |
|---|---|---|---|---|
| Annealed (ASTM B446 Grade 1) | ≥ 827 | 414 | 30 | – |
Delivery Condition and Heat Treatment
Alloy 625 is supplied annealed or solution annealed. It does not harden by heat treatment the way Alloy 718 does; its strength comes from the alloy chemistry. That makes 625 the simpler choice when you need corrosion resistance and fabrication freedom rather than the highest strength. Annealed 625 gives 414 MPa minimum yield, against 1,030 MPa for aged 718.
The alloy work hardens quickly, so machining needs a rigid setup, sharp carbide tooling, low cutting speed and a constant feed. Do not let the tool dwell in the cut. Machine in the annealed condition.
Alloy 625 welds well with matching nickel-alloy filler and does not need post-weld heat treatment for most corrosion service. Tell us your welding process and we confirm the supply condition.
What We Supply Alloy 625 / UNS N06625 In
Where Alloy 625 / UNS N06625 Is Used
Industries: Oil and gas, Aerospace, Chemical, Marine, Nuclear
Compare Alloy 625 / UNS N06625 with Similar Grades
| Alloy 625 / UNS N06625 | Alloy 718 / UNS N07718 | Alloy C-276 / UNS N10276 | Alloy 825 / UNS N08825 | |
|---|---|---|---|---|
| Why consider it | This grade | Precipitation-hardened for higher strength | Better in reducing acids | Lower cost for moderate corrosion |
| Ni % | ≥ 58 | 50–55 | ≥ 51 | 38–46 |
| Cr % | 20–23 | 17–21 | 14.5–16.5 | 19.5–23.5 |
| Mo % | 8–10 | 2.8–3.3 | 15–17 | 2.5–3.5 |
| Nb % | 3.15–4.15 | 4.75–5.5 | – | – |
| Fe % | ≤ 5 | – | 4–7 | ≥ 22 |
| C % | ≤ 0.1 | ≤ 0.08 | ≤ 0.01 | ≤ 0.05 |
| Mn % | ≤ 0.5 | ≤ 0.35 | ≤ 1 | ≤ 1 |
| Si % | ≤ 0.5 | ≤ 0.35 | ≤ 0.08 | ≤ 0.5 |
| Al % | ≤ 0.4 | 0.2–0.8 | – | ≤ 0.2 |
| Ti % | ≤ 0.4 | 0.65–1.15 | – | 0.6–1.2 |
| Co % | ≤ 1 | ≤ 1 | ≤ 2.5 | – |
| B % | – | ≤ 0.006 | – | – |
| Cu % | – | ≤ 0.3 | – | 1.5–3 |
| W % | – | – | 3–4.5 | – |
| V % | – | – | ≤ 0.35 | – |
Alloy 625 / UNS N06625 Questions
Is Alloy 625 the same as Inconel 625?
Yes. Inconel® is the Special Metals trade name for the alloy, which is also called Alloy 625, UNS N06625 and 2.4856 (NiCr22Mo9Nb). All are direct matches in our records. We supply it to ASTM B446 Grade 1 chemistry.
What is the difference between Alloy 625 and Alloy 718?
625 is solution-strengthened and resists corrosion better; 718 is precipitation-hardened and much stronger. Annealed 625 has 414 MPa minimum yield, aged 718 has 1,030 MPa. Choose 625 for corrosive service and welded fabrication, 718 for high-strength parts such as discs, shafts and fasteners.
What is the tensile strength of Alloy 625?
In the annealed condition to ASTM B446 Grade 1, tensile strength is 827 MPa minimum, yield strength is 414 MPa minimum and elongation is 30% minimum. If your specification calls for solution annealed values, send it to us and we confirm.
What temperature can Alloy 625 handle?
It keeps useful strength from cryogenic temperatures up to about 980 °C. For sustained load at the top of that range, tell us the temperature and stress so we can confirm the grade and condition.
Can Alloy 625 be machined and welded?
Yes to both, with care. It work hardens, so machine with sharp carbide tools and a steady feed. It welds with matching nickel-alloy filler and usually needs no post-weld heat treatment.
What is the minimum order for Alloy 625?
OneKaizen quotes by quantity and size. Send us your form, size, condition and quantity and we come back with the supply plan and price.
What is Alloy 625 / UNS N06625 equivalent to?
Alloy 625 / UNS N06625 is the same grade as UNS N06625, EN NiCr22Mo9Nb, DIN W.Nr. 2.4856, JIS NCF625. Close equivalents are GB NS336.
In which forms do you supply Alloy 625 / UNS N06625?
OneKaizen supplies Alloy 625 / UNS N06625 as High Alloy Steel, Round Bars, Inconel Alloys, delivered across India and exported to buyers abroad.
Do you supply Alloy 625 / UNS N06625 with a mill test certificate?
Yes. Every lot ships with an EN 10204 3.1 mill test certificate showing chemistry and mechanical properties, traceable to the heat number.
Data compiled by the OneKaizen metallurgy team from the standards named above. Updated 26 October 2026. Equivalents are nearest matches; confirm critical substitutions against the governing standard and mill certificate.