Hastelloy C-276 vs Hastelloy C-22 vs A453 Gr.660: Which Alloy Fits Your Application?
At FULLERKREG, we regularly help engineers select between high-performance nickel alloys that serve very different purposes. Hastelloy C-276 (N10276) and Hastelloy C-22 (N06022) are both nickel-molybdenum-chromium alloys engineered for extreme corrosion resistance, while A453 Gr.660 (S66286) — also known as A-286 — is an iron-nickel-chromium superalloy designed for high-temperature bolting and fastener applications requiring both strength and oxidation resistance.
This guide provides a direct technical comparison of all three grades per their respective ASTM standards, covering chemical composition and mechanical properties to support your material selection decision.
Alloy Overview
- Hastelloy C-276 (N10276) — A nickel-molybdenum-chromium alloy with tungsten addition. One of the most versatile corrosion-resistant alloys available, with outstanding resistance to both oxidizing and reducing media, pitting, crevice corrosion, and stress corrosion cracking. Governed by ASTM B574.
- Hastelloy C-22 (N06022) — An improved version of C-276 with higher chromium content and lower molybdenum, offering superior resistance to oxidizing media, wet chlorine, and mixed acid environments. Governed by ASTM B574.
- A453 Gr.660 (S66286 / A-286) — A precipitation-hardenable iron-nickel-chromium superalloy with molybdenum, titanium, and boron additions. Designed for high-temperature bolting, fasteners, and structural components up to 700°C. Governed by ASTM A453.
Chemical Composition Comparison
All values are weight percent (%). Min = minimum required; Max = maximum allowed per respective ASTM standard.
Hastelloy C-276 — N10276 (ASTM B574)
| C | Mn | P | S | Si | Cr | Co | Mo | Ni | V | Fe | W | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | — | — | — | — | — | 14.5 | — | 15 | Rem. | — | 4.0 | 3.0 |
| Max | 0.01 | 1.0 | 0.04 | 0.03 | 0.08 | 16.5 | 2.5 | 17 | — | 0.35 | 7.0 | 4.5 |
Hastelloy C-22 — N06022 (ASTM B574)
| C | Mn | P | S | Si | Cr | Co | Mo | Ni | V | Fe | W | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | — | — | — | — | — | 20.0 | — | 12.5 | Rem. | — | 2 | 2.5 |
| Max | 0.015 | 0.5 | 0.02 | 0.02 | 0.08 | 22.5 | 2.5 | 14.5 | — | 0.35 | 6 | 3.5 |
A453 Gr.660 — S66286 / A-286 (ASTM A453)
| C | Mn | P | S | Si | Cr | Ni | Mo | B | Ti | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | — | — | — | — | — | 13.5 | 24.0 | 1.0 | 0.001 | 1.90 | 0.10 | — |
| Max | 0.08 | 2.00 | 0.04 | 0.03 | 1.0 | 16.0 | 27.0 | 1.5 | 0.01 | 2.35 | 0.50 | 0.35 |
Mechanical Properties Comparison
Hastelloy C-276 & C-22 (Annealed)
| Grade | UNS | Condition | Tensile Strength Rm (N/mm²) min | Yield Strength Rp0.2 (N/mm²) min | Elongation A (%) min |
|---|---|---|---|---|---|
| Hastelloy C-276 | N10276 | Annealed | ≥690 | ≥283 | ≥40 |
| Hastelloy C-22 | N06022 | Annealed | ≥690 | ≥310 | ≥45 |
A453 Gr.660 — Mechanical Properties by Grade & Bar Size (Age Hardened)
| Grade / Size | Tensile Strength Rm (N/mm²) min | Yield Strength Rp0.2 (N/mm²) min | Elongation A (%) min | Reduction of Area (%) min | Hardness HB |
|---|---|---|---|---|---|
| Grade A, B, C | ≥895 | ≥585 | ≥15 | ≥18 | 248–341 |
| Grade A, B, C | ≥895 | ≥725 | ≥15 | ≥18 | 248–341 |
| Grade D ≤21/2″ (63.5 mm) | ≥825 | ≥655 | ≥15 | ≥18 | 248–321 |
| Grade D >21/2″ (63.5 mm) | ≥825 | ≥655 | ≥16 | ≥18 | 248–321 |
Key Differences at a Glance
| Parameter | Hastelloy C-276 (N10276) | Hastelloy C-22 (N06022) | A453 Gr.660 (S66286) |
|---|---|---|---|
| Alloy family | Ni-Mo-Cr-W | Ni-Cr-Mo-W | Fe-Ni-Cr superalloy |
| Ni content | Balance (Rem.) | Balance (Rem.) | 24.0–27.0% |
| Cr content (%) | 14.5–16.5 | 20.0–22.5 | 13.5–16.0 |
| Mo content (%) | 15–17 | 12.5–14.5 | 1.0–1.5 |
| W content (%) | 3.0–4.5 | 2.5–3.5 | — |
| Key alloying additions | Mo, W (reducing media resistance) | Cr, Mo, W (oxidizing + reducing) | Ti, B, V (precipitation hardening) |
| Strengthening mechanism | Solid solution | Solid solution | Precipitation hardening (γ’) |
| Tensile Strength min (N/mm²) | 690 | 690 | 825–895 (by grade) |
| Yield Strength min (N/mm²) | 283 | 310 | 585–725 (by grade) |
| Elongation min (%) | 40 | 45 | 15–16 |
| Max service temperature | ~1040°C (oxidizing) | ~1040°C (oxidizing) | ~700°C (bolting) |
| Primary corrosion resistance | Reducing acids, mixed acids, pitting | Oxidizing + reducing, wet Cl₂ | Oxidation resistance (not corrosion-primary) |
| Governing ASTM standard | B574 | B574 | A453 |
Application Selection Guide
Choose Hastelloy C-276 (N10276) when:
- Your process involves reducing acids (hydrochloric, sulfuric, phosphoric) or mixed acid environments
- Resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride-bearing media is critical
- The highest molybdenum content is needed for maximum resistance to reducing conditions
- Typical applications: chemical reactors, heat exchangers, flue gas desulfurization (FGD) scrubbers, pharmaceutical equipment, waste treatment systems, pollution control equipment
Choose Hastelloy C-22 (N06022) when:
- Your environment alternates between oxidizing and reducing conditions, or involves wet chlorine and hypochlorite solutions
- Higher chromium content is needed for superior resistance to oxidizing media compared to C-276
- Improved resistance to pitting and crevice corrosion in ferric and cupric chloride solutions is required
- Typical applications: chemical process vessels, pulp and paper bleaching equipment, pharmaceutical reactors, nuclear waste reprocessing, marine scrubbers
Choose A453 Gr.660 (S66286 / A-286) when:
- High mechanical strength is required at elevated temperatures up to 700°C
- Bolting, fasteners, or structural components must meet ASTM A453 Grade A, B, C, or D requirements
- Non-magnetic austenitic properties are required alongside high strength
- Typical applications: gas turbine bolting, jet engine fasteners, high-temperature pressure vessel studs, aerospace structural components, nuclear reactor internals, exhaust system hardware
FULLERKREG Supply Capabilities
FULLERKREG supplies precision fasteners and engineered components in Hastelloy C-276, Hastelloy C-22, and A453 Gr.660:
- Material Test Certificates (MTC) — EN 10204 3.1 / 3.2 available on request
- ASTM B574 / A453 compliance — rod and bar forms for fastener and structural applications
- A453 Grade A, B, C, D certification — with hardness and mechanical property documentation per size range
- Custom fastener dimensions — non-standard thread forms, head styles, and lengths
- Bulk wholesale pricing — OEM and MRO procurement with competitive lead times
- Global shipping — from our manufacturing base in China to customers worldwide
Need a quote or technical consultation for Hastelloy C-276, C-22, or A453 Gr.660 fasteners? Contact FULLERKREG with your specification and our engineering team will respond promptly.
FULLERKREG — Precision Fasteners. Global Standards. Reliable Supply.