High Carbon Heat-Resistant Stainless Steel for Extreme Temperature Service
1. What is a Seamless TP310H Stainless Steel Pipe?
TP310H Seamless Stainless Steel Pipe is supplied for higher-carbon chemistry for improved high-temperature strength. The size range shown (OD 6–1016 mm; WT 0.5–65 mm) is the overall capability across this product family, not a per-grade commitment. Confirm the specific OD × WT × length combination for the ordered grade in the quotation. The governing specification must be stated on the purchase order: ASTM A312 / ASME SA312. 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.
Manufactured via a seamless process (hot piercing + cold finishing) from a solid billet, TP310H offers:
- Uniform microstructure
- No longitudinal weld seam
- Superior pressure-bearing capability
- Excellent reliability under thermal cycling
The “H” grade indicates a controlled higher carbon content (0.04%–0.10%), which significantly improves:
- Creep rupture strength
- High-temperature mechanical stability
- Resistance to deformation under long-term stress
TP310H retains the excellent oxidation and scaling resistance of TP310, while providing enhanced structural strength for demanding high-temperature applications.
2. Key Features & Technical Advantages
Exceptional High-Temperature Strength (Up to 1150°C)
Performs in continuous service up to 1150°C (2100°F) with excellent resistance to oxidation and scaling.
Superior Creep & Rupture Resistance
Higher carbon content enhances creep strength, reducing deformation under sustained high-temperature stress.
Excellent Oxidation Resistance
High chromium (24–26%) and nickel (19–22%) content forms a stable protective oxide layer in high-temperature air.
Resistance to Carburization & Sulfidation
Performs well in carburizing, nitriding, and sulfur-bearing atmospheres, commonly found in industrial furnaces and petrochemical processes.
Seamless Structural Integrity
Has no longitudinal weld seam, which gives uniform corrosion resistance and mechanical properties along the length, in compliance with:
- ASTM A312
- ASME SA312
Good Fabrication Properties
Despite its high alloy content, TP310H maintains good ductility and toughness, allowing bending, forming, and welding.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for 310H stainless steel.
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| S31009 | 310H | 1.4845 | X8CrNi25-21 | SUH 310 | 06Cr25Ni20 |
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. See the grade designation index.
Chemical Composition
The composition of Stainless Steel 310H is carefully balanced to achieve its superior high-temperature strength and oxidation resistance.
| Cr | Ni | Mn | Si | P | S | Fe | C |
|---|---|---|---|---|---|---|---|
| 24.00 – 26.00 | 19.00 – 22.00 | ≤ 2.00 | ≤ 1.00 | ≤ 0.045 | ≤ 0.030 | Bal | 0.04 – 0.10 |
Data source: ASTM A312-25 / ASME SA312 Table 1, UNS S31009 (TP310H) ≤ heat-analysis acceptance limits; grain size 7 or coarser per Table 5. Confirm the values against the ordered edition and the MTC.
Key Point:
The high Cr-Ni balance provides excellent resistance to oxidation, while the higher carbon content enhances high-temperature strength and creep resistance.
Typical Mechanical Properties
Stainless Steel 310H is specifically designed to maintain its strength and shape in high-stress, high-temperature environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 515 MPa | ≥ 205 MPa | ≥ 35% | ≤ 217 HBW |
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 | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 7.9 g/cm3 | 1400 – 1450 °C approx | 16.5 μm/m·°C (20-100°C) | 14.2 W/m·K (20°C) | 200 GPa | 0.78 × 10⁻⁶ Ω·m (20°C) |
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)
| NPS Designator (Inches) | Permissible Variations in Outside Diameter (Inches) |
| 1⁄8 to 1 1⁄2, inclusive | Over: 1⁄64 in. (0.015 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 1 1⁄2 to 4, inclusive | Over: 1⁄32 in. (0.031 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 4 to 8, inclusive | Over: 1⁄16 in. (0.062 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 8 to 18, inclusive | Over: 3⁄32 in. (0.093 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 18 to 26, inclusive | Over: 1⁄8 in. (0.125 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 26 to 34, inclusive | Over: 5⁄32 in. (0.156 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 34 to 48, inclusive | Over: 3⁄16 in. (0.187 in.) |
| Under: 1⁄32 in. (0.031 in.) |
Tolerance basis: permitted variations per the governing specification stated on this page and the applicable general-requirements standard (ASTM A999 / ASME SA999) for the ordered product form; the wall-thickness and length variations in this section follow the same basis.
The wall thickness tolerances are defined by the nominal wall thickness (t) and the outside diameter (D).
1. Minimum Wall Thickness
The minimum wall thickness at any point on the pipe shall not be more than {12.5%} under the nominal (specified) wall thickness.
2. Maximum Wall Thickness (Percentage Over Nominal)
The maximum allowable wall thickness variation depends on the size and the t/D ratio (ratio of nominal wall thickness to ordered outside diameter):
| NPS Designator (Inches) | t/D Ratio | Permissible Variation (Over Nominal WT) |
| 1/8 to 2, inclusive | All ratios | +20.0% |
| 3 to 18, inclusive | t/D ≤ 5% | +22.5% |
| 3 to 18, inclusive | t/D >5% | +15.0% |
| 20 and larger (Seamless) | t/D ≤ 5% | +22.5% |
| 20 and larger (Seamless) | t/D >5% | +15.0% |
| 20 and larger (Welded) | All ratios | +17.5% |
For pipe ordered to a Specific Cut Length, the standard tolerance is +1⁄8 in. [3.2 mm], -0 in. [0 mm].
Pipe is typically supplied in Single Random Lengths (17 to 24 ft) or Double Random Lengths (38 to 40 ft), unless otherwise specified.
Disclaimer: These tolerances are based on ASTM A999/A999M general dimensional requirements commonly referenced by ASTM A312 and ASTM A790. The full and most current specification document must always be consulted for official design and procurement purposes.
Common Industrial Applications
TP310H seamless pipes are widely used in extreme high-temperature and high-stress environments, including:
Furnace & Heat Treatment Systems
- Radiant tubes
- Burner components
- Furnace linings
- Muffle tubes
Power Generation
- Superheater tubes
- Reheater tubes
- Boiler support components
Petrochemical Industry
- Fluid catalytic cracking (FCC) systems
- Flare tips
- Thermal processing units
Metallurgy & High-Temperature Processing
- Kilns
- Smelting furnaces
- Heat treatment equipment
Waste & Environmental Systems
- Incinerators
- Combustion chambers
- High-temperature exhaust systems
Quality Assurance & Certification
Testing scope is agreed on the purchase order. The following are available and are applied as specified in that order:
EN 10204 3.1 Material Test Certificates (MTC)
as standard; 3.2 by arrangement
PMI (Positive Material Identification)
when specified on the purchase order
Mechanical & Chemical Testing
Corrosion Testing
- Intergranular Corrosion (IGC)
- Grain size analysis (ASTM E112)
Third-Party Inspection
Available on request — ABS, TÜV, BV, DNV, SGS
Frequently Asked Questions
What sizes are available for TP310H seamless pipe?
The overall range is OD 6–1016 mm; WT 0.5–65 mm. Requirements outside this range are reviewed against mill capability on request.
Which specification governs TP310H seamless pipe?
ASTM A312 / ASME SA312 is the governing specification for TP310H seamless pipe. The edition in force at order time is stated on the quotation and purchase order; chemistry, mechanical properties, heat treatment, dimensions and testing are reported against the ordered standard and material heat.
What inspection documents are provided?
Each order is documented with a mill test certificate stating heat chemistry and mechanical test results. EN 10204 3.1 certification, hydrostatic testing, eddy-current or ultrasonic inspection and PMI are performed when specified in the purchase order.
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 NPS and schedule (or actual OD and wall), 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.
For the same grade in tube form, see the TP310H seamless tube. To compare other grades and size combinations, browse the Stainless Steel Seamless Tube category. Minimum order quantity and lead time are confirmed on enquiry against the ordered grade, size and quantity.
