Comprehensive Hardness Guide for Inconel and Hastelloy Alloys
What is the hardness of Inconel alloys?
The hardness of Inconel alloy varies depending on the specific model, but it generally has a high hardness, especially in high temperature environments and can still maintain a good hardness level.
For example, Inconel 625: The hardness range is HB 170-220. It can still maintain high strength and hardness at high temperatures and is suitable for high temperature and high pressure environments.
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What is the hardness (HRC) of Hastelloy C276?
Here are some typical values for reference: Hardness: The Brinell hardness (HB) of Hastelloy C276 is typically around 217-255. Its Rockwell hardness (HRB) is also around 94-98, and its Rockwell C hardness (HRC) is around 20-23.
Both Inconel and Hastelloy are high-performance nickel-based superalloys. While their corrosion resistance is similar, their hardness and mechanical strength can vary significantly depending on the processing method. Inconel is generally known for its higher strength and hardness (e.g., 718 can reach 50 HRC), making it ideal for high-temperature structural components. Hastelloy (e.g., C-276) typically has lower hardness (around 90 HRB or around 20-30 HRC), but its advantage lies in providing excellent corrosion resistance in harsh low-temperature environments.
Hardness Comparison: Inconel vs. Hastelloy (Rockwell C & Brinell)
When comparing these high-temperature alloys, hardness can vary significantly depending on the heat treatment method (solution annealing vs. age hardening).
| Alloy Grade | Hardness (Rockwell C - Typical) | Hardness (Brinell HB - Max) | Tensile Strength (MPa) |
|---|---|---|---|
| Inconel 718 (Aged) | 36 - 44 HRC | 331 - 415 HB | 1240+ |
| Inconel 625 (Annealed) | 15 - 25 HRC | 145 - 220 HB | 827 |
| Hastelloy C276 | 15 - 23 HRC | 210 HB | 790 |
| Hastelloy X | 20 - 25 HRC | 241 HB | 755 |
| Inconel 600 | 10 - 20 HRC | 137 - 180 HB | 550 |
Need a specific hardness for CNC machining?
Please contact GNEE experts for customized hardness specifications
Key Properties and Benefits of Gnee Steel Superalloys
Why Choose GNEE's Inconel and Hastelloy Series Alloys for Your Next Project?
High Temperature Stability:
Our Inconel 718 maintains exceptional hardness and yield strength at temperatures up to 1300°F (704°C).
Excellent Corrosion Resistance:
Hastelloy C276 offers unparalleled resistance to pitting and stress corrosion cracking in corrosive chemical media.
Work Hardening Properties:
These alloys exhibit rapid work hardening properties, making them ideal for high-stress industrial components.
Precision Manufacturing:
We ensure consistent chemical composition, guaranteeing uniform hardness in every batch of plates, bars, and tubes.
How to choose between Inconel alloys and Hastelloy alloys
High Strength/High Temperature Resistance: Use Inconel 718 (hardness 36-45+ HRC).
Extreme Corrosiveness/Reducing Acid Resistance: Use Hastelloy C-276 (hardness approximately 90 HRB).
Machinability: Due to their work-hardening properties, both require specialized high-performance cutting tools.
Inconel Alloys and Hastelloy Alloys Hardness Testing
About GNEE: Your Trusted Superalloy Partner
GNEE (Super Stainless Steel Alloys) is a leading global supplier and manufacturer with over 15 years of expertise in high-performance nickel alloys. We not only sell metals but also provide engineering solutions.
Global Coverage: We serve over 120 countries and have a strong business network in the Middle East, Europe, and Southeast Asia.
Inventory & Customization: We maintain a stock of 5,000 tons of Inconel 625 plates, Hastelloy C276 tubes, and Monel bars, ready for immediate shipment.
Quality Assurance: Every order includes a Factory Test Report (MTR) conforming to EN 10204 3.1. We conduct in-house ultrasonic testing, hardness testing, and PMI testing.
Certifications: ISO 9001:2015, SGS, and BV certified.
Professional Packaging & Fast Global Shipping
We understand the paramount importance of protecting the surface and integrity of our superalloys.
Packaging: Waterproof paper and plastic film + reinforced wooden crate (compliant with IPPC standards) + steel straps for reinforcement, ensuring safe sea transport.
Delivery time: 3-7 days for in-stock products; 15-30 days for customized products.
Gnee Steel Inconel Alloy Packing
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅ Over 18 years of export experience, products sold to more than 80 countries
✅ Certified by ISO, SGS, and BV
✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars
✅ Custom processing services available – including cutting, polishing, CNC machining, and packaging
✅ Fast delivery within 7-15 days, supported by global logistics partners
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
About Gnee Steel
Gnee Steel is a professional manufacturer of nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy 800, Incoloy 800H/HT, Incoloy 825, Monel 400, Monel K500, and other high-temperature alloy materials. We specialize in the production and sales of alloy materials. Gnee Steel's products are widely used in aerospace, chemical, power generation, automotive, nuclear energy, and other fields, and we can provide customized alloy material solutions according to customer needs. For inquiries about alloy material prices or customized alloy material solutions, please feel free to contact us via email at ss@gneemetal.com for a quote.
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Contact us for the latest export price quote for Inconel metal
FAQ
Q: Can Inconel 718 be machined in its hardest state?
A: Yes, but it's difficult. We recommend rough machining in the annealed state followed by finish grinding after precipitation hardening (aging) for optimal precision.
Q: Does Hastelloy C276 require heat treatment after welding?
A: Generally, C276 can be used immediately after welding because it effectively inhibits the formation of grain boundary precipitates, thus maintaining its hardness and corrosion resistance.
Q: How can I verify the hardness of my order?
A: GNEE provides a digital Rockwell hardness test report for each batch of products before shipment. You can also request inspection by a third-party inspection agency (SGS/TUV).
Q: What is the hardness of Inconel alloys?
A: Typical hardness range of Inconel 718
Aging the alloy increases its hardness to 36–44 HRC or 360–450 HV. Combining cold working with aging further increases the maximum hardness to 45–50 HRC or 460–520 HV.
Q: What is the difference between Inconel 625 and Hastelloy C-276?
A: Both Inconel 625 and Hastelloy C-276 are nickel-chromium-molybdenum based alloys. They both exhibit excellent corrosion resistance and good strength. Comparing the two alloys, Inconel 625 has a higher chromium content, while Hastelloy C-276 has a higher molybdenum content.
Q: Why is welding Hastelloy alloys so difficult?
A: While Hastelloy is generally weldable, it also presents some challenges that require careful attention to achieve high-quality welds: slow-flowing molten pool and shallow penetration: compared to stainless steel or carbon steel, nickel-based alloys like Hastelloy tend to have a more viscous (slow-flowing) molten pool.
