Stainless Steel 904L Pipe
The 904L Pipe made from Stainless Steel is a low-carbon austenitic alloy that has been engineered for applications in extremely corrosive settings with significant chloride concentrations..The elevated levels of nickel, chromium, molybdenum, and copper in SS 904L pipe enhance its resistance to sulfuric and phosphoric acids, as well as to stress corrosion cracking, when compared to conventional grades like 316L and 317L.The properties of the 904L stainless steel pipes render them applicable in critical process piping in which extended service life and stability of the material are demanded.
Stellar Alloys Steel Pipes and Tubes offers roll pipes of Stainless Steel 904L and 904L-welded Stainless Steel of materials of the designation UNS N08904 and EN 1.4539 that are manufactured to the ASTM A312 TP904L and ASTM B677 standards, respectively. Standard sizes, schedules and wall thickness of pipes are available to handle specific requirements of the project in terms of pressure and temperature. Every SS 904L pipe is delivered with the certification of EN 10204 3.1 mill test that guarantees the chemical structure, mechanical characteristics, and dimensional property. Common uses are chemical processing plants, desalination systems, heat exchangers and acid handling pipelines where corrosion strength and dependability is important.
Stainless Steel 904L Pipe Supplier and Manufacturer in India
Stellar Alloys Steel Pipes and Tubes is a large supplier and manufacturer of Stainless Steel 904L pipes that meet the needs of the industrial piping where the resistance to strong acids and chlorides is very important. The high content of nickel and molybdenum and low content of carbon make SS 904L pipe largely popular in chemical processing, desalination, heat exchangers, and high-purity systems. Our 904L stainless steel pipes are supplied in seamless and welded models that are produced to standards ASTM A312 TP904L and ASTM B677 and include the UNS N08904 and EN 1.4539 material specifications.
In projects which use mixed grades of stainless steel, Stainless Steel Pipes and Tubes are usually procured with 904L pipes to ensure compatibility between corrosion-resistant piping systems. Alternatives may also be considered by engineers depending on the conditions of the service; which include Stainless Steel 304 Pipe, Stainless Steel 317L PipeorStainless Steel 310 Pipewhich may be used in temperature-driven or cost-sensitive applications. Stellar Alloys Steel Pipes and Tubes has made it easy to trace its chemical composition, mechanical properties and dimensional compliance with critical service environments through the provision of at least AN 10204 3.1 mill test certification on each SS 904L pipe supplied.
Types & Popular Variants 904L Seamless Pipe & Welded Tube
Selecting the right 904L product form depends on pressure/temperature, corrosion risk and fabrication needs. This section maps out seamless vs. welded/ERW and round/square/hex options with schedules, finishes (BA/AP) and typical uses, so you can match ASTM A312/A269/B677 products to your duty cycle. Stellar Alloys Steel Pipes and Tubes maintains application-ready stock, U-bends and cut-to-length supply for fast mobilization.
Stainless Steel 904L Pipe
ASTM A312 TP904L Welded Pipe
SS 904L Seamless Pipe
Equivalent Material Grades of 904L Stainless Steel
Use these cross-references to line up drawings, MTOs and purchase specs when 904L appears under different naming systems. Metallurgical equivalence refers to the grade chemistry; dimensions and tolerances still follow the cited product standards and always confirm against project requirements.
| System | Designation | Region / Standard Body | Typical Product Standards (examples) | Common Synonyms / Notes |
| UNS | N08904 | USA (Unified Numbering System) | ASTM A312 (pipe), ASTM A269 (tubing), ASTM B677 (UNS N08904 pipe/tube), ASTM A240 (plate/sheet), ASTM A249 (welded HX tube) | Often called 904L; purchase-friendly identifier for global sourcing |
| EN / W.Nr. | 1.4539 | Europe (EN) | EN 10216-5 (seamless stainless tubes), EN 10217-7 (welded stainless tubes), EN 10088-2/-4 (flat products) | Steel name: X1NiCrMoCu25-20-5 |
| AISI | 904L | USA (legacy AISI grade name) | Uses ASTM product standards listed above | Legacy naming; for POs prefer UNS N08904 / EN 1.4539 |
| JIS | SUS 904L | Japan (JIS) | JIS G3463 (boiler & HX tubes), JIS G4304/G4305 (plate/sheet/strip) | Equivalent chemistry to UNS N08904 |
| AFNOR | Z2NCDU 25-20-5 | France (NF/AFNOR) | Aligns to EN 10088 family for products | Legacy French designation for 904L |
Verify cross-references and applicable product standards against your project specification and QA plan before procurement.
Key Features & Applications of Alloy 904L Pipes
Engineered for aggressive chemistries, 904L delivers corrosion resistance well beyond 316L/317L while keeping a fully austenitic, easily fabricated structure. Use this section to quickly judge where 904L provides lifecycle value versus alternative stainless or duplex grades
Features
Below are the performance drivers that make UNS N08904 / EN 1.4539 a reliable choice in mixed acids and chlorides. Pair with suitable fillers, post-weld cleaning and the right surface finish for your service.
High resistance to sulfuric, phosphoric and acetic acids; strong pitting/crevice resistance in chlorides.
Low carbon for improved intergranular corrosion resistance after welding.
Good toughness and formability; stable austenitic structure from cryogenic to elevated temperatures.
Applications
These are typical duty areas where 904L reduces unplanned downtime and extends change-out intervals. Select schedules/finishes to match pressure, temperature and cleanliness needs.
Acid pickling lines, fertilizer plants, chemical reactors and transfer piping.
Handles mixed acids and chloride drag-in in pickling/etching lines; copper and molybdenum additions improve resistance in sulfuric-rich loops and off-spec cleaning solutions.
Desalination and seawater systems, evaporators and heat exchangers.
Better pitting/crevice resistance than 316L in warm, aerated seawater; suitable for condenser tubes, brine heaters and splash/crevice zones around supports and tube sheets.
Pulp & paper bleach plants; pharma & high-purity tubing; flue-gas scrubbers.
Resists chloride-bearing bleach liquors and acidic condensates; BA/electropolished tubes help limit rouging and biofilm in high-purity circuits; robust against acidic SOx/Cl-laden scrubbing media.
Complete Range of AISI 904L Stainless Steel Pipe Material
Use this map to connect product forms with the right standards and documentation. Apply drawing-specific tolerances when tighter control is required.
| Item | Details |
| Standards | ASTM A312 (pipe), ASTM A269 (tubing), ASTM B677 (UNS N08904 pipe/tube), ASTM A249 (welded heat-exchanger tubes) |
| Tolerances | ASTM A312 and ASTM A269; special tolerances to approved drawing |
| Documentation | EN 10204 3.1 standard; 3.2 with third-party inspection on request |
904L EN 1.4539 Pipe Tensile & Yield Strength
Values below are typical room-temperature baselines for screening and MTOs. Use project MTCs and code allowables for final design.
| Property | Typical Minimum |
| Yield Strength (0.2%) | ~220 MPa |
| Tensile Strength | ~490 MPa |
| Elongation | ≥35% |
SS 1.4539 Pipe Modulus & Temperature Range
These constants support stress checks, deflection estimates and thermal growth calculations. Temperature range is indicative and needs derating and code rules at higher service temperatures.
| Property | Value |
| Elastic Modulus (E) | ~200 GPa |
| Poisson’s Ratio | ~0.3 |
| Recommended Service Window | −196 °C to ~400 °C (verify derating and code allowables) |
Dimensions, Sizes & Schedules of 904L SS Pipe
This section compiles practical size ranges and schedules for 904L in seamless and welded forms. Use it to align layouts, stock planning and cut-length requirements.
904L Stainless Steel Pipe Sizes & Dimensions (mm)
Get the OD, WT, and length options at a glance for each product form. Pick SRL, DRL or cut-to-length to match installation and handling.
| Form | OD Range (mm) | WT Range (mm) | Lengths |
| Seamless Pipe (A312/B677) | 6 – 219 | 0.5 – 20 | SRL / DRL / Cut |
| Welded Pipe (A312/B677) | 12 – 1219 | 0.8 – 20 (by schedule) | SRL / DRL / Custom |
| Seamless Tube (A269/B677) | 6 – 114 | 0.5 – 6 | Straight / Coils / U-bend |
| Welded Tube (A269/A249) | 6 – 152 | 0.5 – 3.0 | Straight / U-bend |
904L Pipe Schedule & Wall Thickness (Complete Schedule List)
Refer to the full schedule set used for pressure design and availability. Cross-check with code allowables and service media before finalizing.
| Schedule | Description |
| SCH 5S | Thin-wall, lightweight option for low-pressure utilities and non-critical transfer lines; verify erosion limits in high-velocity service. |
| SCH 10S | Light-duty process service with better mechanical margin than 5S; common for low/medium pressure at ambient to moderate temperatures. |
| SCH 20 | Mid-light wall where modest pressure and temperature apply; useful step up when 10S is marginal. |
| SCH 40S (STD) | General-purpose “standard” wall for mainstream process piping; widely available and easy to source fittings. |
| SCH 80S | Heavy-duty wall for higher design pressures/temperatures; preferred for steam lines, cyclic duty, and corrosive media with allowance. |
| SCH 120 | Extra-heavy wall where pressure margins, corrosion allowance or mechanical loads demand added thickness. |
| SCH 160 | Very heavy wall for severe pressure/temperature combinations; check weight/handling and weld heat input planning. |
| XXS (on request) | Maximum wall for extreme pressure or machining stock; availability is size-dependent and may require mill runs. |
Schedule 40 Alloy 904L Pipe Thickness & Dimensions
These Schedule 40 samples help with quick take-offs and comparisons. Confirm against your drawings and current mill tolerances.
| NPS | OD (mm) | SCH 40 WT (mm) |
| 1/2″ | 21.3 | 2.77 |
| 3/4″ | 26.7 | 2.87 |
| 1″ | 33.4 | 3.38 |
| 2″ | 60.3 | 3.91 |
| 4″ | 114.3 | 6.02 |
| 6″ | 168.3 | 7.11 |
| 8″ | 219.1 | 8.18 |
Chemical and Physical Properties of UNS N08904 Stainless Steel Pipe
| Element | C | Mn | Si | P | S | Cr | Ni | Mo | Cu | N |
| Wt% | ≤0.02 | ≤2.0 | ≤1.0 | ≤0.045 | ≤0.035 | 19-23 | 23-28 | 4.0-5.0 | 1.0-2.0 | ≤0.10 |
Mechanical & Physical Properties of 904L Pipes
See the nickel, chromium, molybdenum and copper ranges that drive corrosion performance. Keep within spec to maintain pitting and crevice resistance.
| Property | Symbol | Unit | Typical value | Notes / test method |
| Yield strength, 0.2% proof | Rp0.2 | MPa | ~220 | Longitudinal, annealed; per ASTM E8/E8M |
| Ultimate tensile strength | Rm | MPa | ~490 | Longitudinal, annealed; per ASTM E8/E8M |
| Elongation (gauge length A5) | A5 | % | ≥ 35 | Tube/pipe product, annealed; ASTM E8/E8M |
| Hardness (max) | HRB | – | ≤ 90 | ASTM E18; typical procurement cap |
904L Seamless Pipe Weight Chart (ASTM B677 UNS N08904)
Use this chart for rapid kg/m estimates during MTOs and shipping plans. Reconfirm with final OD/WT and length tolerances.
Density assumed 8000 kg/m³; confirm against drawings and MTCs.
| OD (mm) | WT (mm) | Approx. ID (mm) | Weight (kg/m) |
| 21.30 | 2.77 | 15.76 | 1.29 |
| 21.30 | 3.73 | 13.84 | 1.65 |
| 26.70 | 2.87 | 20.96 | 1.72 |
| 26.70 | 3.91 | 18.88 | 2.24 |
| 33.40 | 3.38 | 26.64 | 2.55 |
| 33.40 | 4.55 | 24.30 | 3.30 |
| 42.20 | 3.56 | 35.08 | 3.46 |
| 42.20 | 4.85 | 32.50 | 4.55 |
| 48.30 | 3.68 | 40.94 | 4.13 |
| 48.30 | 5.08 | 38.14 | 5.52 |
| 60.30 | 3.91 | 52.48 | 5.79 |
| 60.30 | 5.54 | 49.22 | 8.08 |
| 73.00 | 5.16 | 62.68 | 9.06 |
| 73.00 | 7.01 | 58.98 | 12.14 |
| 88.90 | 5.49 | 77.92 | 12.11 |
| 88.90 | 7.62 | 73.66 | 16.42 |
| 114.30 | 6.02 | 102.26 | 16.04 |
| 114.30 | 8.56 | 97.18 | 22.69 |
| 141.30 | 7.11 | 127.08 | 22.03 |
| 141.30 | 9.53 | 122.24 | 29.05 |
| 168.30 | 7.11 | 154.08 | 26.26 |
| 168.30 | 10.97 | 146.36 | 40.21 |
| 219.10 | 8.18 | 202.74 | 42.45 |
| 219.10 | 12.70 | 193.70 | 64.51 |
| 273.00 | 9.27 | 254.46 | 60.26 |
| 273.00 | 12.70 | 247.60 | 81.30 |
| 323.90 | 9.53 | 304.84 | 73.77 |
| 323.90 | 12.70 | 298.50 | 97.35 |
904L Pipe Pressure Rating & Tube Pressure Chart
Indicative Pressure by Wall Thickness (Barlow) - NPS 2″ (OD 60.3 mm)
Barlow approximation with S = 120 MPa at ~room temperature, for comparison only. Finalise per ASME B31.1/B31.3 with temperature/joint factors.
| WT (mm) | Indicative Pressure (bar) |
| 2.77 | 115.6 |
| 3.91 | 166.4 |
| 5.54 | 242.8 |
| 7.01 | 315.7 |
| 8.74 | 406.8 |
Indicative Pressure by Wall Thickness (Barlow) - NPS 4″ (OD 114.3 mm)
Same assumptions as above.
| WT (mm) | Indicative Pressure (bar) |
| 3.05 | 65.8 |
| 6.02 | 133.4 |
| 8.56 | 194.3 |
| 11.13 | 258.9 |
Tolerance Chart for 904L Stainless Steel Tubes
Know the standard OD, WT, ovality and straightness limits before ordering. Specify tighter tolerances where process is critical.
| Parameter | Typical Limit | Reference |
| OD tolerance | ±0.5% (min ±0.15 mm) | ASTM A269/A312 (typical) |
| WT tolerance | ±10% | ASTM A269/A312 (typical) |
| Ovality | Within OD tolerance | ASTM A269/A312 |
| Straightness | ≤1.5 mm per 1000 mm | ASTM A269/A312 |
Surface Finish and Welding of Stainless Steel 904L Pipe
Finish and welding practice strongly influence corrosion performance and cleanliness. Choose the combination that fits service media and validation needs.
SS 904L Tubing Surface Finish Options
Select BA, AP, polished or electropolished based on fouling risk and hygiene. Add passivation where cleanliness and corrosion behavior matter.
BA (Bright Annealed) for clean ID, low-roughness services.
AP (Annealed & Pickled) for general process duty.
Polished (180-600 grit) for architectural/pharma; electropolish on request.
Passivation to improve cleanliness/corrosion behavior.
AISI 904L Pipe Welding Guidelines
Use compatible fillers and controlled heat input to protect corrosion resistance. Back-purge and post-weld clean to keep IDs process-ready.
Use ER385 (904L) or over-alloyed fillers; maintain moderate heat input and interpass ≤150 °C.
Back-purge for root quality; clean and pickling/passivation after welds.
For chloride-rich or reducing acids, match filler and post-weld cleaning to service.
Testing and Inspection of Stainless Steel 904L Pipe
Quality controls confirm identity, integrity and dimensional compliance. This section outlines the test set typically supplied with documentation.
SS 904L Pipe Inspection & Test Reports
Expect PMI, hydro/pneumatic, mechanical and NDT results tied to heat numbers. EN 10204 3.1 is standard, with 3.2 available via TPI.
PMI heat/lot level; Hydro/Pneumatic leak tests per order.
NDT: Eddy-current (thin wall), UT (heavy wall), RT for weld seams when specified.
Mechanical: Tensile, hardness, flattening/flaring, reverse bend per spec.
Dimensional: OD/WT/ovality/straightness per ASTM & drawings.
Docs: EN 10204 3.1 MTC, packing lists, heat maps, barcode traceability; 3.2 via TPI on request
Price List of 904L Stainless Steel Pipe in India
Pricing varies with OD/WT, finish and nickel surcharge. Use these entries for budgeting and request a firm quote for live orders.
| OD × WT (mm) | Condition | Typical MOQ | Indicative Pricing |
| 21.3 × 2.77 | AP | 200 m | Price on Request |
| 33.4 × 3.38 | AP | 200 m | Price on Request |
| 60.3 × 3.91 | AP | 100 m | Price on Request |
| 88.9 × 5.49 | AP | 50 m | Price on Request |
| 114.3 × 6.02 | BA/AP | 50 m | Price on Request |
Why Choose Stellar Alloys Steel Pipes and Tubes for 904L Stainless Steel Pipe & Tubes?
Partner with a supplier focused on certified material, tight tolerances and clean documentation. Our stock breadth and export logistics keep projects moving on schedule.
Certified material, every lot: 904L (UNS N08904 / EN 1.4539) with EN 10204 3.1, PMI and full traceability; compliance to ASTM A312/A269/B677 and general requirements to A999.
Application-ready inventory: Seamless and welded in round/square/rectangular/hex; BA/AP; U-bends and long lengths; quick call-offs.
Precision that boosts uptime: Tight OD/WT/ovality and clean IDs reduce fouling and pressure drop, extending exchanger/tube-bundle run length.
Welding & QA discipline: Qualified WPS/PQR, controlled interpass and post-weld cleaning; EC/UT/RT and hydro options aligned to project specs.
Global logistics support: MDR packs, correct HSN, seaworthy packing and export documentation to keep audits clean and deliveries predictable.
Related Links
Frequently Asked Questions About Stainless Steel 904L Pipe
317L has higher molybdenum than 316L, giving it better pitting/crevice corrosion resistance. Both are austenitic, low-carbon grades; 317L is typically selected for slightly more aggressive chloride environments.
Yes, due to its higher nickel, molybdenum and copper content, 904L typically costs more than 304/316L. The premium offsets with longer life in aggressive media (e.g., sulfuric acid, seawater).
In normal atmospheres and many process environments, 904L resists rusting very well. In highly oxidizing acids or contaminated chloride conditions, correct grade selection and surface finish remain important.
904L is austenitic; duplex grades have a mixed austenite-ferrite structure with higher strength and often better stress-corrosion cracking resistance. Selection depends on chemistry, temperature and mechanical requirements.