What is TP904L Seamless Stainless Steel Pipe?
TP904L Seamless Stainless Steel Pipe is supplied for high nickel-molybdenum-copper alloying for reducing-acid and chloride service. 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 or ASTM B677, only as supported by the order and MTC. 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 using a seamless process (hot extrusion / hot piercing + cold drawing or cold rolling), TP904L pipes feature:
- Uniform microstructure
- No longitudinal weld seam
- Superior pressure resistance
- Enhanced reliability in critical applications
The alloy is characterized by:
- Low carbon content (≤0.020% per the ordered specification for the actual grade) to reduce the risk of sensitization
- High Nickel (23–28%) for corrosion and SCC resistance
- High Molybdenum (4.0–5.0%) for pitting resistance
- Copper (1.0–2.0%) for excellent resistance to reducing acids
This combination makes TP904L one of the most corrosion-resistant stainless steels available.
Key Features and Technical Advantages
Outstanding Resistance to Strong Acids
TP904L exhibits exceptional resistance to reducing acids, especially:
- Sulfuric Acid (H₂SO₄)
- Phosphoric Acid (H₃PO₄)
- Acetic Acid
This makes it ideal for chemical processing and acid handling systems.
Superior Pitting & Crevice Corrosion Resistance
With a high PREN (Pitting Resistance Equivalent Number) due to Mo and Ni content, TP904L performs excellently in:
- Chloride-rich environments
- Seawater
- Offshore applications
Excellent Stress Corrosion Cracking (SCC) Resistance
The high nickel content significantly improves resistance to chloride-induced SCC, making it suitable for:
- Marine environments
- Chemical plants
- Heat exchanger systems
Fully Austenitic & Non-Magnetic Structure
TP904L maintains:
- Stable austenitic microstructure
- Very low magnetic permeability
- Excellent performance after cold working
High Mechanical Strength & Pressure Integrity
Manufactured according to ASTM A312 / ASME SA312 / EN 10216-5, ensuring:
- Reliable performance under high pressure
- Consistent wall thickness
- Safe operation in critical systems
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Stainless Steel TP317L .
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| N08904 | 904L | 1.4539 | X1NiCrMoCu25-20-5 | SUS890L | 015Cr21Ni26Mo5Cu2 |
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 synergy of Mo + Cu + high Ni is what gives TP904L its superior acid resistance and corrosion performance.
| Cr | Ni | P | S | Mo | Cu | Mn | Si | C |
|---|---|---|---|---|---|---|---|---|
| 19.00 – 23.00 | 23.00 – 28.00 | ≤ 0.045 | ≤ 0.035 | 4.00 – 5.00 | 1.00 – 2.00 | ≤ 2.00 | ≤ 1.00 | ≤ 0.02 |
Data source: ASTM A312-25 / ASME SA312 Table 1, TP904L row ≤ heat-analysis acceptance limits. Confirm the values against the ordered edition and the MTC.
Typical Mechanical Properties
Stainless Steel 904L is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 490 MPa | ≥ 215 MPa | ≥ 35% | ≤ 192 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 |
|---|---|---|---|---|---|
| 8.0 g/cm3 | 1300 – 1390 °C approx. | 16.5 μm/m·°C (20-100°C) | 13.9 W/m·K (20°C) | 195 GPa | 0.85 × 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
TP904L seamless stainless steel pipes are widely used in industries requiring extreme corrosion resistance:
Chemical & Petrochemical Industry
Heat exchangers, reactors, acid transfer pipelines
Oil & Gas Offshore Systems
Bleaching systems, FGD units
Pulp & Paper Industry
Sour gas pipelines, offshore seawater cooling systems
Pharmaceutical & Food Processing
High-purity pipelines, sterilization systems
Hydrometallurgy
Copper, nickel, and zinc extraction processes
Quality Assurance & Inspection
Each TP904L pipe undergoes strict quality control to ensure full compliance with international standards:
Testing & Inspection
- Positive Material Identification (PMI), when specified on the purchase order
- Non-Destructive Testing (NDT), as specified:
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
- Hydrostatic Testing
- Corrosion Testing:
- ASTM A262 (Intergranular Corrosion)
- Pitting resistance tests
Certification & Traceability
- EN 10204 3.1 Material Test Certificates (MTC) as standard; 3.2 by arrangement
- Heat treatment records
- Full traceability from raw material to finished product
- Third-party inspection available on request: SGS, BV, TUV, DNV, ABS
Frequently Asked Questions
What sizes are available for TP904L 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 TP904L seamless pipe?
ASTM A312 / ASME SA312 or ASTM B677, only as supported by the order and MTC is the governing specification for TP904L 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 TP904L 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.
