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What is the difference between Inconel and Incoloy?
Short answer
Inconel alloys are nickel-based (about 50–75% nickel) for severe heat and corrosion. Incoloy alloys are iron-nickel-chromium with about 30–46% nickel, which lowers cost. Incoloy 800H and 800HT are creep-resistant furnace alloys, and Incoloy 825 is an acid- and sour-service alloy.
Inconel vs Incoloy at a glance
| Inconel | Incoloy | |
|---|---|---|
| Nickel content | ≈ 50 – 75% | ≈ 30 – 46% |
| Base | Ni | Fe-Ni |
| Typical use | Heat and severe corrosion | Furnaces (800 series), acids (825) |
| Cost | Higher | Lower |
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.
Matching duties
| Duty | Typical choice |
|---|---|
| Reformer and cracker parts | Incoloy 800HT |
| Sulphuric acid and sour gas | Incoloy 825 |
| Caustic and chloride SCC risk | Inconel 600 |
| Seawater and chemical service with strength | Inconel 625 |
A common confusion
The names sound alike but the alloys are not interchangeable. 825 is not a cheaper 625; their chemistry, strength and corrosion behaviour differ. Always order by UNS number.
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Frequently asked questions
Is Incoloy magnetic?
No, the Incoloy alloys are austenitic and non-magnetic.
Which is better for high temperature?
Both families are used. Incoloy 800H/HT is the usual choice for creep-loaded furnace parts, and Inconel 600/601 for oxidation and carburisation resistance.
What is the main difference between Inconel and Incoloy?
Inconel alloys are nickel-base. Incoloy alloys are iron-nickel-chromium with less nickel and lower cost. Incoloy 800H/HT are creep-resistant furnace alloys, and 825 is an acid- and sour-service alloy.
When should I choose Inconel?
Maximum corrosion or temperature resistance.
When should I choose Incoloy?
Cost-effective heat and acid resistance.