What Is a Seamless Hastelloy C-4 Tube?
Seamless Hastelloy C-4 Tube – High-Performance Corrosion-Resistant Tubing
Key Features of Seamless Hastelloy C-4 Tubing
- Exceptional High-Temperature Stability
- Maintains mechanical strength and corrosion resistance at temperatures ranging from 650°C to 1040°C (1200°F to 1900°F).
- Resistant to embrittlement, even after prolonged high-temperature exposure.
- Outstanding Corrosion Resistance
- Performs reliably against a wide range of oxidizing and reducing acids.
- High chromium and molybdenum content enhances resistance to pitting, crevice corrosion, and intergranular attack.
- High Pressure and Stress Tolerance
- Seamless construction ensures safety under extreme internal pressures and mechanical stress.
- Ideal for high-performance piping and heat exchanger applications.
- Superior Weldability
- Can be welded using standard techniques without risk of post-weld corrosion.
- Supports complex industrial fabrications while maintaining long-term durability.
Product Specifications and Data
Hastelloy C-4 Seamless Tube is supplied for nickel-molybdenum-chromium alloy performance in reducing and thermally cycled service. Available size range: OD 6–257 mm; WT 0.5–35 mm. The governing specification must be stated on the purchase order: ASTM B622 / ASME SB622, UNS N06455. Chemistry, mechanical properties, heat treatment, dimensional tolerance, NDT and certification must be reported against the ordered standard and material heat; do not treat typical values as guaranteed acceptance limits.
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| N06455 | Hastelloy C-4 | 2.4610 | NiMo16Cr16Ti | NW6455 | NS3305 / NS335 (legacy) |
Grade correspondence does not make ASTM, ASME, EN, JIS and GB delivery requirements interchangeable. Confirm chemistry, heat treatment, mechanical properties, dimensions, testing and certification against the purchase specification. Approximate or unconfirmed correspondences retain their qualification. See the grade designation index.
Chemical Composition
The composition of C-4 is carefully balanced to achieve its superior corrosion resistance and high-temperature stability.
| C | Si | Mn | P | S | Cr | Mo | Ni | Ti | Co | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.015 | ≤0.08 | ≤1.00 | ≤0.040 | ≤0.030 | 14.00–18.00 | 14.00–17.00 | Bal | ≤0.70 | ≤2.00 | ≤3.00 |
Data source: ASTM B622 / ASME SB622, UNS N06455 ≤ heat-analysis acceptance limits per the governing standard. Confirm the values against the ordered edition and the MTC.
Typical Mechanical Properties
C-4 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation |
|---|---|---|
| ≥ 690 MPa | ≥ 276 MPa | ≥ 40% |
Note: Typical values for reference only — not acceptance limits. Mechanical properties are reported on the MTC against the ordered standard, product form, condition and test temperature.
Typical Physical Properties
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
| Density | 8.64 g/cm³ |
|---|---|
| Melting Point | 1335-1380 °C |
| Thermal Expansion | 10.8 μm/m·°C |
| Thermal Conductivity | 10.1 W/m·K |
| Modulus of Elasticity | 208 GPa |
| Electrical Resistivity | 1.25 × 10⁻⁶ Ω·m |
Note: Typical values for reference only — not acceptance limits. Physical and mechanical properties are reported on the MTC against the ordered standard, product form and condition.
Size Tolerance Chart (mm)
Cold-Finished Pipes and Tubes:
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
|---|---|---|---|
| 0.500 to 5⁄8, excl. | ±0.005 | 12.7 to 15.8, excl. | ±0.127 |
| 5⁄8 to 1 1⁄2, incl. | ±0.0075 | 15.8 to 38.1, incl. | ±0.190 |
| Over 1 1⁄2 to 3 1⁄2, incl. | ±0.010 | Over 38.1 to 88.9, incl. | ±0.254 |
| Over 3 1⁄2 to 4 1⁄2, incl. | ±0.015 | Over 88.9 to 114.3, incl. | ±0.381 |
| Over 4 1⁄2 to 6, incl. | ±0.020 | Over 114.3 to 152.4, incl. | ±0.508 |
| Over 6 to 6 5⁄8, incl. | ±0.025 | Over 152.4 to 168.3, incl. | ±0.635 |
Tolerance basis: permitted variations per the governing specification stated on this page and the applicable general-requirements standard (ASTM B829) referenced by the product specification ASTM B622 / ASME SB622, for the ordered product form; the wall-thickness and length variations in this section follow the same basis.
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
|---|---|---|---|
| 2 1⁄2 to 5 1⁄2, excl. | ±0.031 | 63.5 to 139.7, excl. | ±0.787 |
| 5 1⁄2 to 9 1⁄4, incl. | ±0.047 | 139.7 to 234.9, incl. | ±1.19 |
| Condition | Specified/Calculated Nominal OD (Inches) | Permissible Variation (Wall Thickness) |
|---|---|---|
| Cold-Finished | 0.500 to 5⁄8, excl. | ±15.0% |
| 5⁄8 to 4 1⁄2, incl. | ±10.0% | |
| Over 4 1⁄2 to 6 5⁄8, incl. | ±12.5% | |
| Hot-Finished | 2 1⁄2 to 9 1⁄4, incl. | ±12.5% |
Applications of Seamless Hastelloy C-4 Tube
- Chemical processing and petrochemical plants
- Marine and seawater desalination systems
- Nuclear and power generation facilities
- High-temperature industrial heat exchangers
Why Choose Hastelloy C-4 Tubing
Seamless Hastelloy C-4 Tubes combine durability, reliability, and high corrosion resistance, making them the preferred choice for industries where safety and longevity are critical. Their seamless design and superior alloy composition ensure optimal performance in even the harshest environments.
Frequently Asked Questions
What sizes are available for C-4 seamless tube?
Which specification governs C-4 seamless tube?
What inspection documents are provided?
Technical review: page data reviewed by the Xinzhe technical desk on 2026-09-27. Chemistry acceptance limits are compiled from the governing ASTM/ASME specification stated on this page; mechanical and physical values are typical reference data and are not acceptance guarantees. Values must be confirmed against the standard edition in force at order time and the material test certificate.
Ready to Request a Quotation?
Send the size (OD and wall or schedule), quantity, length, end finish and the inspection items you need as acceptance criteria — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
