Physical properties
| Density | 8.31 | g/cm³ |
Informative values: they vary with composition, condition and test method. Use the governing standard or measured mill data for pressure and heat-transfer calculations.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements6 elements | |||
| Ni | Nickel | 55 – 59% | |
| Cr | Chromium | 19 – 22.5% | |
| Fe | Iron | Bal. | |
| Mo | Molybdenum | 7 – 9.5% | |
| Nb | Niobium | 2.75 – 4% | |
| Ti | Titanium | 1 – 1.7% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual4 elements | |||
| Al | Aluminium | ≤ 0.35% | |
| C | Carbon | ≤ 0.03% | |
| Mn | Manganese | ≤ 0.35% | |
| Si | Silicon | ≤ 0.2% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Bar, forgings and forging stock | Solution treated, aged | ≥ 1034 (150 ksi) | ≥ 827 (120 ksi) | ≥ 20 | Also specified: Reduction of area Z ≥ 35 % · Hardness ≤ 393 HBW |
| Tube and pipe | |||||
| Seamless tube, Type 1 | Solution annealed, aged | ≥ 1035 (150 ksi) | ≥ 827 (120 ksi) | ≥ 20 | Also specified: Hardness ≤ 43 HRC |
| Several forms | |||||
| Bar and wire | Solution treated, as delivered | ≥ 758 (110 ksi) | ≥ 310 (45 ksi) | ≥ 30 | |
| Bar and wire | Solution treated, aged | ≥ 1137 (165 ksi) | ≥ 827 (120 ksi) | ≥ 20 | |
Hardness requirement
Required by the standard — ≤ 393 HB (43 HRC max)
A maximum, not a minimum. 725 and 925 are exempt from stress-rupture testing — their high-temperature acceptance criterion sits on hardness instead.
More detail 1
For H₂S service, NACE MR0175 / ISO 15156-3 caps solution-annealed and aged 725 at the same 43 HRC, or 44 HRC up to 204 °C without elemental sulfur.
Stress-rupture requirement
No stress-rupture test is required for this grade. A certificate carrying no rupture data is compliant and is not grounds for rejection.
Where this grade is recommended
Matched in 6 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| HPHT wells | Oil & Gas | 150 – 230 °C | 1 / 7 | 93 |
| Packers & downhole tools | Oil & Gas | ≤ 150 °C | 2 / 7 | 93 |
| Wellhead & Christmas tree | Oil & Gas | ≤ 120 °C | 2 / 7 | 92 |
| Downhole tubing (sour H₂S/CO₂) | Oil & Gas | ≤ 150 °C | 4 / 10 | 90 |
| Subsea lines, risers & manifolds | Oil & Gas | ≤ 60 °C | 4 / 7 | 87 |
| Subsea connectors & hydraulics | Marine & Offshore | ≤ 40 °C | 5 / 5 | 86 |
Designations & equivalents
| Trade name(s) | Inconel 725 |
| ASTM / AISI | B637 / B805 / B983 (bar & wire) |
| NACE sour service | ISO 15156-3: solution-annealed and aged ≤43 HRC |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
3 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is Alloy 725 · UNS N07725?
Alloy 725 · UNS N07725 — Ni corrosion-resistant. High-strength corrosion-resistant age-hardened grade for sour downhole components
What is the maximum service temperature of N07725?
Typically about 540 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of N07725?
The specified minimum tensile strength is 1137 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover N07725?
ASTM B805, ASTM B637, ASTM B983
Where is N07725 typically used?
HPHT wells (Oil & Gas); Packers & downhole tools (Oil & Gas); Wellhead & Christmas tree (Oil & Gas); Downhole tubing (sour H₂S/CO₂) (Oil & Gas)
In which forms is N07725 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
Or email us: info@kochlin.com