Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy vs Inconel
Verdict in one sentence: Incoloy is a nickel-iron-chromium family with iron as the matrix base (30 to 35 percent Ni, balance Fe), Inconel is a nickel-chromium family with nickel as the matrix base (above 50 percent Ni). The two are distinct alloy classes registered to different UNS prefixes (Incoloy N088xx, Inconel N066xx), with different specifications, different welding procedures and different price levels. Both trade names originate from the International Nickel Company (INCO) and are now owned by Special Metals (Huntington Alloys). The choice between Incoloy and Inconel turns on three controlling factors: chloride stress-corrosion resistance (Inconel wins above 45 percent Ni threshold), carburization and nitriding resistance (Inconel wins on high-Ni furnace work), and cost-per-creep-life in plain oxidation service (Incoloy wins on lower mill price). This page lays out the chemistry diffs, decision matrix, and welding-procedure implications.
Request a Quote on Incoloy 800H or Inconel 600 / 625 Material
Family Overview
| Family | Matrix base | Typical Ni content | UNS prefix | Common grades |
|---|---|---|---|---|
| Incoloy | Iron-base Ni-Fe-Cr | 30 to 45 percent | N088xx | 800, 800H, 800HT, 825, 925, A-286 |
| Inconel | Nickel-base Ni-Cr | 50 to 75 percent | N066xx / N076xx | 600, 601, 617, 625, 718, X-750 |
Chemistry Side-by-Side Examples
| Element | Incoloy 800H (N08810) | Inconel 600 (N06600) | Inconel 625 (N06625) |
|---|---|---|---|
| Nickel (Ni), percent | 30.0 to 35.0 | 72.0 min | 58.0 min |
| Iron (Fe), percent | balance, ~39.5 | 6 to 10 | 5 max |
| Chromium (Cr), percent | 19.0 to 23.0 | 14.0 to 17.0 | 20.0 to 23.0 |
| Carbon (C), percent | 0.05 to 0.10 | 0.15 max | 0.10 max |
| Molybdenum (Mo), percent | n/a | n/a | 8.0 to 10.0 |
| Niobium (Nb+Ta), percent | n/a | n/a | 3.15 to 4.15 |
| Al + Ti combined, percent | 0.30 to 1.20 | n/a | 0.40 + 0.40 max each |
When Each Family Wins
| Service condition | Winner | Why |
|---|---|---|
| Plain high-temp oxidation to 815 deg C | Incoloy 800H | Lower mill price per kg, ASME Section VIII qualified |
| Chloride stress-corrosion cracking | Inconel 600 or 625 | Ni above 45 percent threshold is immune |
| Carburizing furnace atmosphere | Inconel 600 (or 601) | Higher Ni resists carbon ingress |
| Nitriding furnace atmosphere | Inconel 600 (or 601) | Higher Ni resists nitrogen pickup |
| Dual corrosion + high-temp service | Inconel 625 | Mo + Nb resist halogenated streams |
| Sulfuric / phosphoric acid corrosion | Incoloy 825 | Mo + Cu shift Ni-Fe-Cr toward acid resistance |
| ASME Section VIII pressure vessel to 815 deg C | Incoloy 800H | Code-qualified; lower cost than Inconel 617 |
| Aerospace combustor and gas turbine | Inconel 718, X-750, 625 | Higher creep + fatigue floor at extreme temperature |
Common Confusion Matrix
The naming convention causes routine confusion in procurement: Incoloy 800H is sometimes mis-specified as "Inconel 800H" on drawings that originated outside the petrochemical sector. The two are not equivalent; Inconel 800H does not exist as a registered UNS designation. Where a drawing says "Inconel 800H" the design intent is almost always Incoloy 800H (UNS N08810) and the procurement team should query the project for clarification before mill release. Similarly, Incoloy 825 is sometimes mis-named "Inconel 825" though the registered UNS designation N08825 puts it firmly in the Incoloy family.
Welding Filler Differences
| Base metal | GTAW filler | SMAW electrode |
|---|---|---|
| Incoloy 800H (N08810) | ERNiCr-3 (Inconel 82) | ENiCrFe-2 (Inconel 182) |
| Inconel 600 (N06600) | ERNiCr-3 (Inconel 82) | ENiCrFe-3 (Inconel 182) |
| Inconel 625 (N06625) | ERNiCrMo-3 (Inconel 625 filler) | ENiCrMo-3 |
| Incoloy 825 (N08825) | ERNiCrMo-3 (Inconel 625 filler) | ENiCrMo-3 |
The filler families overlap (ERNiCr-3 serves both Incoloy 800H and Inconel 600) but each base-metal welding procedure must be qualified separately per ASME Section IX.
Price Differential
Mill price differential between Incoloy 800H and Inconel 600 / 625 tracks the London Metal Exchange nickel and chromium spot prices on the heat date. Indicative ranges: Inconel 600 is 30 to 50 percent more expensive per kilogram than Incoloy 800H; Inconel 625 is 60 to 100 percent more expensive. Where the service envelope permits Incoloy 800H, the cost saving over Inconel 600 / 625 is material to project economics and is the primary driver behind specifying 800H for ASME Section VIII pressure vessels above 540 deg C. For project-specific pricing, contact TorqBolt sales.
Related Comparison Pages
- Incoloy 800 vs 800H vs 800HT: internal grade family
- Incoloy 800H vs Inconel 600: matrix-base diff
- Incoloy 800H vs Inconel 625: high-temp + corrosion diff
- Incoloy 800H vs Incoloy 825: creep vs corrosion variant
Naming History and Trademark Ownership
The Incoloy and Inconel trade names were both created by the International Nickel Company (INCO) in the 1930s to 1950s to differentiate the iron-base and nickel-base nickel-chromium product families. INCO Huntington Alloys later became Inco Alloys International, then Special Metals Corporation, and is now part of Precision Castparts Corporation. The two trademark families are now both owned by Special Metals (Huntington Alloys), with manufacturing licensed to second-source mills under chemistry windows registered as UNS designations with ASTM Committee B02. The technical bulletins published by Special Metals remain the primary single-source datasheets for both families; secondary mill datasheets from licensed second-source producers must conform to the same chemistry windows and the same ASTM source specifications (B407 / B408 / B409 / B564 for Incoloy 800H, B167 / B168 for Inconel 600, B443 / B444 / B446 / B564 for Inconel 625).
TorqBolt Forms in Incoloy 800H
- Seamless pipe + seamless tube to ASTM B407
- Round bar to ASTM B408
- Plate + sheet to ASTM B409
- Forgings + flanges + fittings to ASTM B564
- Fasteners: stud bolts, hex bolts, nuts, washers
- ASME Section VIII pressure-vessel material
- API 660 heat-exchanger tube for refinery and petrochemical service
Frequently Asked Questions
Q. Are Incoloy and Inconel the same?
No. Incoloy is a nickel-iron-chromium family with iron as the matrix base (30 to 35 percent Ni, balance Fe). Inconel is a nickel-chromium family with nickel as the matrix base (above 50 percent Ni). They are different alloy classes registered to different UNS prefixes (Incoloy N088xx, Inconel N066xx).
Q. Why does the name include INCO?
Both trade names originate from the International Nickel Company (INCO). Inconel is a Ni-Cr alloy family for very high temperature and chloride stress-corrosion resistance. Incoloy is a Ni-Fe-Cr alloy family that gives most of the Inconel benefit at lower nickel content and lower price. The trade names are owned by Special Metals (Huntington Alloys).
Q. Is Incoloy cheaper than Inconel?
Generally yes. Lower nickel content (30 to 35 percent for Incoloy versus 50 to 75 percent for Inconel) drives a lower mill price per kilogram. The price differential depends on London Metal Exchange nickel and chromium spot prices on the heat date and is typically 25 to 40 percent for plate and 15 to 30 percent for forgings.
Q. Can Incoloy 800H be substituted for Inconel 600 in furnace service?
Only with engineering review. Inconel 600 wins in pure carburizing and nitriding furnace atmospheres because its higher nickel content resists carburization attack better than Incoloy 800H. Incoloy 800H wins on cost-per-creep-life in plain high-temperature oxidation service up to 815 deg C. The two are not direct substitutes.
Q. Which is welded with which filler?
Incoloy 800H is welded with ERNiCr-3 (Inconel 82) GTAW filler or ENiCrFe-2 (Inconel 182) SMAW electrode. Inconel 600 is welded with ERNiCr-3 (Inconel 82) GTAW filler or ENiCrFe-3 (Inconel 182) SMAW electrode. The filler families overlap but each base-metal welding procedure must be qualified separately per ASME Section IX.
Satisfaction Survey
