Monel vs. Inconel vs. Incoloy vs. Hastelloy: [+Full Alloy Comparison Chart]
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Compare Monel, Inconel, Incoloy, and Hastelloy alloys by strength, corrosion resistance, and 3D printing use.
Introduction
Nickel-based alloys are essential materials in industries requiring high performance. Among the most widely used are Monel, Inconel, Incoloy, and Hastelloy—each with distinct compositions, strengths, and industrial applications.
This article provides a practical, side-by-side comparison of these key alloys to help engineers, material specialists, designers, and procurement teams confidently choose the right material based on technical demands, manufacturing methods (including additive manufacturing), and real-world operating conditions.
Related Reading: Explore Inconel 3D Printing
At Unionfab, we're excited to announce that we now offer advanced metal 3D printing services for high-performance nickel alloys, including Inconel 625, Inconel 718, and Hastelloy X. Contact us to learn more!
What are Monel, Inconel, Incoloy, and Hastelloy?
About the Alloy Names
Monel, Inconel, Incoloy, and Hastelloy are registered trade names that originated from two companies—Special Metals Corporation and Haynes International.
Over time, they’ve evolved into general industrial terms representing entire families of nickel-based superalloys, even if manufactured by other suppliers.
Name | Name Origin | Company |
|---|---|---|
Monel | Named after Ambrose Monell, INCO executive | Special Metals Corporation |
Inconel | "INCO" + "el" (short for alloy) | Special Metals Corporation |
Incoloy | "INCO" + variation of "alloy" | Special Metals Corporation |
Hastelloy | Coined by Haynes International, no fixed linguistic root | Haynes International |
These names now serve as shorthand for categories of nickel alloys with similar behavior, regardless of the original brand or manufacturer.
Chemical Composition Table
The table below outlines the approximate chemical composition (by weight %) of four commonly used high-performance nickel alloys: Monel 400, Inconel 625, Incoloy 825, and Hastelloy C-276:
Element | Monel 400 | Inconel 625 | Incoloy 825 | Hastelloy C-276 |
|---|---|---|---|---|
Nickel (Ni) | 63.0 min | 58.0 min | 38.0–46.0 | Balance (~57%) |
Copper (Cu) | 28.0–34.0 | N/A | N/A | N/A |
Chromium (Cr) | N/A | 20.0–23.0 | 19.5–23.5 | 14.5–16.5 |
Iron (Fe) | 2.0–3.0 | ≤ 5.0 | ≥ 22.0 | 4.0–7.0 |
Molybdenum (Mo) | N/A | 8.0–10.0 | 2.5–3.5 | 15.0–17.0 |
Manganese (Mn) | ≤ 2.0 | ≤ 0.5 | ≤ 1.0 | ≤ 1.0 |
Carbon (C) | ≤ 0.3 | ≤ 0.1 | ≤ 0.05 | ≤ 0.01 |
What This Means for Material Selection:
Monel 400, with high copper content, offers outstanding resistance to saltwater and hydrofluoric acid but lacks significant chromium or molybdenum for oxidizing or acidic environments.
Inconel 625 balances nickel, chromium, and molybdenum, making it suitable for both high-heat and corrosive conditions.
Incoloy 825, with higher iron and moderate nickel, is cost-effective and weldable but less resistant to extreme acids.
Hastelloy C-276 contains high molybdenum and chromium, excelling in reducing acid environments like sulfuric or hydrochloric systems.
Performance Comparison
At-a-Glance Alloy Properties Summary
The table below offers a quick comparison of key performance metrics:
Property | Monel | Inconel | Incoloy | Hastelloy |
|---|---|---|---|---|
High-Temperature Strength | ★★★☆☆ | ★★★★★ | ★★★☆☆ | ★★★★☆ |
Corrosion Resistance | ★★★★★ | ★★★★★ | ★★★☆☆ | ★★★★★ |
Oxidation Resistance | ★★★☆☆ | ★★★★★ | ★★★★☆ | ★★★☆☆ |
Acid Resistance | ★★★☆☆ | ★★★☆☆ | ★★★☆☆ | ★★★★★ |
Weldability | ★★★★☆ | ★★★☆☆ | ★★★★☆ | ★★★☆☆ |
3D Print Compatibility | ★★☆☆☆ | ★★★★★ | ★★☆☆☆ | ★★★☆☆ |
Machinability | ★★★★☆ | ★★★☆☆ | ★★★★☆ | ★★★☆☆ |
Relative Cost | ★★★★☆ (High) | ★★★★★ (Very High) | ★★★☆☆ (Medium) | ★★★★★ (Very High) |
One-on-One Alloy Comparisons
Monel vs. Inconel
Composition: Nickel-Copper vs. Nickel-Chromium
Corrosion Resistance: Monel is excellent in seawater; Inconel excels in high-temperature oxidation environments
Applications: Monel is used in marine pumps and valves; Inconel is ideal for turbine blades and exhaust systems
Monel 400 Valve Component
Source: htpipe.com
Source: additivalab.com
Inconel vs. Incoloy
Composition: Inconel contains more nickel; Incoloy contains more iron
Fabrication: Incoloy is easier to weld and form
Applications: Inconel is used in aerospace; Incoloy in chemical and heat exchanger systems
Inconel 625 3D Print
Source: txjscl.com
Incoloy 825 Heat Exchanger Tube
Source: gaofatech.com
Inconel vs. Hastelloy
Chemical Environment: Inconel is best in oxidizing environments; Hastelloy thrives in reducing and acidic conditions
Applications: Inconel for aerospace and gas turbines; Hastelloy for chemical processing and acid service
Source: Zeyon, Inc.
Monel vs. Incoloy
Corrosion vs. Temperature: Monel outperforms in saltwater; Incoloy is more stable at high temperatures
Cost: Incoloy is more affordable and easier to process
Hastelloy vs. Monel
Acid Resistance: Hastelloy offers superior protection
Marine Environments: Monel is preferred due to excellent chloride resistance
Application-Based Alloy Selection
The following guide helps identify which alloy to choose based on industry needs.
Industry | Recommended Alloy | Reason |
|---|---|---|
Marine Engineering | Monel | Exceptional performance in seawater |
Chemical Processing | Hastelloy | Outstanding resistance to strong acids |
Aerospace | Inconel | Maintains strength at extreme temperatures |
Oil & Gas | Incoloy or Inconel | Balance of heat resistance and weldability |
Select the right alloy by evaluating operating conditions, chemical exposure, and mechanical load requirements.
Additive Manufacturing Compatibility
Which Alloys Work Best for Metal 3D Printing?
Some nickel-based alloys are well suited for additive manufacturing (AM), particularly laser powder bed fusion (LPBF).
Alloy | Powder Availability | Thermal Stability | Crack Risk | Typical Use in AM |
|---|---|---|---|---|
Inconel 625 | Widely available | High | Low | Aerospace, energy |
Inconel 718 | Widely available | High | Low | Jet engines, AM tooling |
Hastelloy X | Limited | High | Moderate | Chemical reactors |
Hastelloy C-22 | Limited | Moderate | Moderate | Acid-resistant structures |
Monel 400 | Rare | Moderate | High | Not typically used in AM |
Incoloy 825 | Rare | Moderate | High | Not common in AM |
Note: When alloys like Monel or Incoloy are required but not printable, hybrid strategies (e.g., printing core structures and machining functional surfaces) can be used.
Source: be-cu.com
Detailed Mechanical Property Comparison
Chart A: Mechanical Properties Table
Property | Monel 400 | Inconel 625 | Incoloy 825 | Hastelloy C-276 |
|---|---|---|---|---|
Tensile Strength (MPa) | 480 – 620 | 827 – 1034 | 585 – 690 | 690 – 827 |
Yield Strength (MPa) | 170 – 345 | 414 – 517 | 220 – 310 | 283 – 345 |
Elongation (%) | 35 | 30 – 50 | 30 – 40 | 40 – 50 |
Hardness (Rockwell B) | 70 – 90 | 88 – 94 | 85 – 92 | 89 – 95 |
Density (g/cm³) | 8.8 | 8.44 | 8.14 | 8.89 |
Chart B: Corrosion Performance Table
Environment | Monel 400 | Inconel 625 | Incoloy 825 | Hastelloy C-276 |
|---|---|---|---|---|
Seawater | Excellent | Good | Moderate | Moderate |
Hydrochloric Acid (HCl) | Poor | Moderate | Poor | Excellent |
Sulfuric Acid (H₂SO₄) | Fair | Moderate | Moderate | Excellent |
Oxidizing Atmospheres | Fair | Excellent | Excellent | Moderate |
Reducing Environments | Moderate | Good | Moderate | Excellent |
Chart C: Maximum Service Temperature and Heat Treatment
This table summarizes the upper temperature limits and heat treatment capabilities of each alloy. It helps engineers understand which materials retain structural integrity under prolonged high-temperature exposure and whether post-processing can enhance their properties.
Alloy | Max Service Temp (°C) | Heat Treatable? | Notes |
|---|---|---|---|
Monel 400 | ~480°C | No | Strengthened via cold working |
Inconel 625 | ~982°C | Yes | Solid solution strengthened |
Incoloy 825 | ~540°C | No | Annealed for corrosion service |
Hastelloy C-276 | ~1040°C | No | High thermal stability |
Cost & Fabrication Considerations
Cost Insight: Incoloy is most cost-effective; Hastelloy and Inconel are premium options.
Machining Difficulty: Inconel and Hastelloy require carbide tooling and precise process control.
Welding Characteristics: Incoloy offers good weldability; Inconel and Hastelloy require preheat and post-weld treatment.
This table outlines practical manufacturing considerations for each alloy, including welding method compatibility and machining challenges.
Alloy | Weldability | Machining Notes | Recommended Welding Method |
|---|---|---|---|
Monel 400 | Excellent | Work hardens; use low speeds | GTAW/TIG, MIG with matching filler |
Inconel 625 | Moderate | Work hardens rapidly; requires carbide tools | Preheat + post-weld aging |
Incoloy 825 | Good | Good formability and weldability | Common with ERNiCrMo-3 filler |
Hastelloy C-276 | Moderate | Needs control to avoid heat cracking | Low heat input TIG or pulsed MIG |
Final Selection Guide
Quick Alloy Selector
Use Case | Recommended Alloy | Reason |
|---|---|---|
Saltwater corrosion | Monel | Best resistance to chlorides |
High temperature use | Inconel | Excellent mechanical strength >1100°C |
Acidic environment | Hastelloy | Excellent acid resistance |
Fabrication ease | Incoloy | Weldable and cost-efficient |
Additive Manufacturing | Inconel, Hastelloy | Proven AM performance and availability |
Conclusion
Nickel-based alloys such as Monel, Inconel, Incoloy, and Hastelloy offer specialized performance in the most demanding industries. Selecting the appropriate material involves balancing performance characteristics, cost, and manufacturability.
Unionfab provides end-to-end solutions for metal additive manufacturing, including material consultation, DfAM (Design for Additive Manufacturing), and full-scale production services.
Optimize Your Project with Unionfab
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Whether you're developing prototypes, functional parts, or production-ready batches, our engineering support and industrial platforms help deliver precision and performance.
Contact us to learn how to start your nickel alloy 3D printing project!
