On this page 8 sections
Should I use Inconel 625 or Hastelloy C276?
Short answer
Use C276 for hot, contaminated reducing acids, wet chlorine and hypochlorite, where its 16% molybdenum and 4% tungsten outperform 625. Use 625 for seawater, flue-gas desulphurisation and general corrosive service that also needs strength, where it is usually more economical and widely available.
Inconel 625 vs Hastelloy C276 at a glance
| Property | Inconel 625 | Hastelloy C276 |
|---|---|---|
| UNS | N06625 | N10276 |
| EN | 2.4856 | 2.4819 |
| Family | Nickel-chromium (Ni-Cr) alloy | Nickel-chromium-molybdenum (Ni-Cr-Mo) alloy |
| C (%) | 0.10 max | 0.010 max |
| Cr (%) | 20.0 – 23.0 | 14.5 – 16.5 |
| Ni (%) | 58.0 min | Balance |
| Mo (%) | 8.0 – 10.0 | 15.0 – 17.0 |
| Ti (%) | 0.40 max | — |
| V (%) | — | 0.35 max |
| W (%) | — | 3.0 – 4.5 |
| Al (%) | 0.40 max | — |
| Fe (%) | 5.0 max | 4.0 – 7.0 |
| Tensile strength | 827 MPa (120 ksi) | 690 MPa (100 ksi) |
| Yield strength | 414 MPa (60 ksi) | 283 MPa (41 ksi) |
| PREN | ≈ 51 | ≈ 68 – 76 |
| Density | 8.44 g/cm³ | 8.89 g/cm³ |
| Magnetic | Non-magnetic. | Non-magnetic. |
| Typical use | Seawater piping and offshore systems | Chemical reactors and heat exchangers |
Which should you choose?
There's no universal "winner": the right choice depends on service conditions, codes and cost. Share your conditions with us for a recommendation.
Reading the chemistry
Availability matters on projects
625 is produced in a wider range of pipe, plate, bar and fitting sizes, and is also the standard weld-overlay alloy. C276 lead times can be longer for less common sizes, which can decide the choice on fast-track jobs.
Products in both grades
Related guides, comparisons and articles
Guides
Frequently asked questions
Is C276 better in seawater?
Both resist seawater extremely well. 625 is usually sufficient and more economical; C276 is chosen when acid contamination is also present.
Which has higher strength?
625 has higher minimum yield and tensile strength in the annealed condition.
What is the main difference between Inconel 625 and Hastelloy C276?
Both are Ni-Cr-Mo alloys. C276 has about 16% Mo and 4% W, which gives superior resistance to reducing acids and severe chloride environments. 625 is stronger and more economical for many seawater and general chemical uses.
When should I choose Inconel 625?
Seawater, FGD and general corrosive service needing strength.
When should I choose Hastelloy C276?
Hot contaminated mineral acids, wet chlorine and hypochlorites.
Can Inconel 625 replace Hastelloy C276?
Only when the design, code and specification allow it. Strength, corrosion resistance and temperature limits differ, so substitution must be approved by the design authority.
Which has better pitting resistance, Inconel 625 or Hastelloy C276?
Typical PREN: Inconel 625 ≈ 51, Hastelloy C276 ≈ 68 – 76. A higher PREN generally means better chloride pitting resistance.