EN
904L stainless steel is a low-carbon, high-alloy austenitic grade identified as UNS N08904 and EN 1.4539. It is considered for demanding process environments where corrosion resistance is a key selection issue. Its properties, applications and price need to be assessed against the product form and operating conditions.
For buyers, the main risk is treating a grade name as a complete specification. A plate, pipe or bar order still needs dimensions, delivery condition and inspection requirements. This guide explains the material data and purchasing questions without treating 904L as an automatic replacement for 316L or promising suitability for every acid or marine environment.
What Is 904L Stainless Steel?
904L belongs to the austenitic stainless steel family. Chromium, nickel, molybdenum and copper form its principal alloying system. The following figures are reference chemistry from Sandmeyer's Alloy 904L sheet, not a certificate for a particular shipment. Use the applicable product specification and agreed inspection documents for order acceptance.
| Element | Published range or maximum |
|---|---|
| Chromium | 19.0–23.0% |
| Nickel | 23.0–28.0% |
| Molybdenum | 4.0–5.0% |
| Copper | 1.0–2.0% |
| Manganese | 2.00% maximum |
| Silicon | 1.00% maximum |
| Iron | Balance |
Selected elements only. This table is not a complete chemical acceptance specification. Confirm all required elements, limits and the applicable standard edition for the product being purchased.
Carbon is also important: Alleima lists a maximum of 0.020% for its 2RK65 material. Low carbon helps limit sensitization risk associated with welding; it does not eliminate every weld-related corrosion risk. Use this as a separately identified producer reference rather than merging different data sheets into one acceptance standard. [2]
Properties of 904L Stainless Steel
Numerical properties are useful only when their basis is clear. Sandmeyer's plate-oriented data sheet reports the following room-temperature mechanical references. These are source-specific information, not engineering allowable stresses or a universal guarantee for every pipe, bar and cold-worked product.
| Property | Reference value | Basis |
|---|---|---|
| 0.2% offset yield strength | 220 MPa | 20°C; source lists minimum values unless specified |
| Ultimate tensile strength | 490 MPa | 20°C; same source basis |
| Hardness | 70–90 HRB | Published reference range at 20°C |
| Density | 7.95 g/cm³ | Published physical-property reference |
| Thermal conductivity | 12.9 W/(m K) | At 100°C |
For a pressure component, the design code and product specification determine what values and tests are acceptable. Do not use a room-temperature tensile figure alone to establish a working pressure, service temperature or safe load.
Corrosion and fabrication limits
Sulfuric-acid performance depends on temperature, concentration and contaminants; halide-containing acids can exceed 904L's resistance. Its work hardening also affects machining. These qualifications matter more than an unqualified claim of corrosion immunity or easy machining. [1]
Alleima lists solution-annealed and pickled or bright-annealed seamless tube, and describes welding procedures and heat-input considerations for its 2RK65 material. Treat that guidance as a source for procedure review, not permission to use one welding method or delivery condition for every order. [2]
Before selecting the grade: provide the process medium, concentration, operating and cleaning temperatures, chloride exposure and fabrication details. Where magnetic permeability or sour-service compliance matters, specify the test or project requirement rather than relying on the grade name alone.
904L Stainless Steel vs. 316L
904L contains substantially more nickel and molybdenum than the named 316L reference below, together with a copper addition. That is a meaningful material difference, but the purchase decision still depends on the process environment. Compare chemistry on the same basis: typical producer values are not specification limits.
| Comparison | 904L | 316L |
|---|---|---|
| Typical producer chemistry | Ultra 904L: Cr 19.8%, Ni 24.2%, Mo 4.3%, Cu 1.40% | Supra 316L/4404: Cr 17.2%, Ni 10.1%, Mo 2.1% |
| Material family | High-alloy austenitic grade with deliberate copper addition | Molybdenum-alloyed austenitic grade |
| Corrosion selection | Considered for more demanding process environments, including selected sulfuric-acid conditions | Used across process industries; actual corrosion suitability still depends on the medium and temperature |
| Fabrication and supply | Confirm a grade-specific welding/machining procedure and the required product form | Also requires appropriate procedures; an existing 316L specification does not automatically approve a change to 904L |
| Quotation comparison | Compare matching dimensions, quantity, finish, processing, documents and delivery terms. No fixed price ratio applies to every order. | |
Chemistry values above are Outokumpu typical compositions for the named products, not universal grade limits or batch acceptance values. The 904L range table earlier and these typical compositions use different reference bases. A higher alloy content alone does not approve substitution or establish a safe service condition.
If a drawing or project specification already names 316L, obtain approval before substituting another grade. A material change can affect more than the purchase price: the inspection plan, fabrication procedure and documentation may also need review.
Applications of 904L Stainless Steel
Outokumpu lists chemical processing, pulp bleaching, flue-gas cleaning, seawater handling and heat exchangers among Ultra 904L application areas. These describe where the grade is evaluated; they do not guarantee suitability for every installation. [3]
| Application area | Information needed for selection |
|---|---|
| Chemical process equipment | Medium, concentration, impurities, operating and cleaning temperatures |
| Heat exchangers and piping | Fluids on each side, pressure, temperature, product standard and fabrication route |
| Pulp bleaching and gas cleaning | Process chemistry, cleaning cycle and corrosion history |
| Seawater-handling systems | Water conditions, temperature, flow, crevices and maintenance regime |
Specify whether you need raw material, blanks or cut lengths. Material supply is separate from the design and manufacture of a complete tank, exchanger or pressure system. This distinction helps prevent a material enquiry from being mistaken for an equipment contract.
904L Stainless Steel Price: What Affects a Quote?
A useful 904L price comparison requires more than a price per kilogram. State the product form and dimensions first, then align quantity, surface, processing, inspection documents, packing and delivery terms. There is no fixed multiplier against 316L that reliably describes every order.
For example, compare a cut plate quotation with another quotation for the same finished dimensions and cutting scope. For pipe, match outside diameter, wall thickness, length and manufacturing route. Otherwise, two quoted prices may cover different products or services.
Voyage Metal reviews enquiries manually before confirming the offer. Availability, final price and delivery are established for the particular order; this article is not a live stock or price list.
Product Forms, Specifications and Documents
Voyage Metal can discuss 904L sheet, plate, coil, bar and pipe requirements, including custom dimensions subject to order confirmation. Product forms should not share one unqualified dimensional range or acceptance specification.
For flat products, begin with thickness, width and length. Pipe enquiries need outside diameter, wall thickness and length, or a specified nominal size and schedule. Bar enquiries need diameter and length; coil enquiries should include width and any handling requirements.
ASTM A240 is a flat-product reference, while Alleima's material sheet lists tube and pipe references including ASTM A269 and A312. Select the standard, edition and manufacturing route appropriate to the application rather than applying a plate standard to a pipe order. [2]
For product-form navigation, see our stainless steel sheet and plate range or stainless steel pipe range. These are category pages; send your specific 904L requirements for confirmation.
State MTC, EN 10204 3.1 or third-party inspection requirements before order acceptance. Document availability and scope, tolerances, surface condition, processing and packing are confirmed for the order, rather than assumed from the product name.
904L Stainless Steel FAQs
Can 904L replace 316L?
Not automatically. Review the service conditions, design code, fabrication requirements and purchase specification. Obtain the responsible engineer's approval where a specified grade would change.
Does a property table guarantee delivered performance?
No. A published reference table explains the material. The agreed product standard, condition, inspection requirements and supplied documentation define the purchase acceptance criteria.
Are custom sizes available?
Custom size enquiries are welcome. Send the dimensions, tolerances, quantity and required condition. The team confirms whether the requested combination and processing scope can be supplied before accepting the order.
[1] Sandmeyer Alloy 904L specification sheet, reference chemistry and properties.
[2] Alleima 2RK65 material data, tube condition and product-standard references.
[3] Outokumpu Ultra 904L, application areas. Producer references do not establish Voyage Metal inventory or certification.
[4] Outokumpu Supra 316L/4404, typical producer composition and grade description.
Discuss Your 904L Material Requirements
Send your specification or drawing so our team can review the material and supply requirements before preparing a quotation.
Include: grade, product form, dimensions, tolerance, surface or delivery condition, quantity, standard, document requirements, application, packing and destination.
Email: [email protected]
WhatsApp: +86 189 1799 4375
Each enquiry is reviewed manually. Final specifications, documents and supply terms are confirmed for the order.