SS 904L SheetASTM A240 UNS N08904 · Manufacturer, stockist & exporter, India
Also sold as Alloy 904L · UNS N08904 · W.Nr 1.4539 · 2RK65
SS 904L sheet is Alloy 904L (UNS N08904) rolled below 3/16" (4.76 mm) thick for formed, pressed and lined parts under ASTM A240. It is a super-austenitic stainless steel with high nickel, molybdenum and copper, chosen for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is SS 904L Sheet?
SS 904L sheet is a super-austenitic stainless steel with high nickel, molybdenum and copper supplied as sheet to ASTM A240 (UNS N08904). Buyers specify it for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. It is also sold as Alloy 904L, UNS N08904, W.Nr 1.4539.
- What it is
- Super-austenitic stainless steel with high nickel, molybdenum and copper
- Standard
- ASTM A240
- Thickness
- Below 3/16" (4.76 mm)
- Density
- 7.95 g/cm³
- Supplied as
- Annealed · 2B, BA, No.4
- Best at
- Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water
SS 904L Sheet Specification & Sizes
| Material standard | ASTM A240 · ASME SA-240 |
|---|---|
| General requirements | ASTM A480 — dimensions, tolerances and finishes |
| Grade | SS 904L · UNS N08904 · W.Nr 1.4539 |
| Thickness | Below 3/16" (4.76 mm) — thicker is plate |
| Width × length | 1000 / 1219 / 1250 / 1500 mm × 2000 / 2438 / 2500 / 3000 mm, or cut to size |
| Condition & finish | Annealed · 2B, BA or No.4 |
| Cutting | Cut to size and to width |
| Testing | PMI · UT (plate) · intergranular corrosion · hardness, on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection · packing list · certificate of origin |
Sheet or plate?
Both are ordered under ASTM A240, so buyers often mix them up. The line is thickness: below 3/16" is sheet, 3/16" and over is plate. If your drawing calls for 3/16" (4.76 mm) or more, you need SS 904L plate.
SS 904L Sheet Finishes — Which to Order
Sheet is bought for its surface as much as its chemistry. The finish is set at the mill and cannot be fixed later without polishing cost, so name it on the order. Finish designations for 904L sheet follow ASTM A480.
| Finish | How it is made | Choose it for |
|---|---|---|
| 2D | Cold rolled, annealed and pickled | Dull matt grey. Holds lubricant well, so it is the finish for deep drawing and parts that are painted or hidden. |
| 2B | As 2D, then a light skin pass on polished rolls | Smooth, moderately reflective. The standard general-purpose sheet finish and the one to order if the drawing says nothing. |
| BA (2R) | Bright annealed in a protective atmosphere | Bright, highly reflective and very smooth. Used for reflectors, hygienic and decorative surfaces; ask for protective film. |
| No.4 | Abrasive polished with a directional grain | Brushed look that hides handling marks. Food equipment, architecture and panels. |
SS 904L Sheet Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Chromium | As specified |
| Molybdenum | As specified |
| Copper | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Iron | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS N08904.
SS 904L Sheet Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS N08904 — Annealed plate & sheet.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.95 g/cm³ |
| Melting range | 1300 – 1390 °C |
| Magnetic | Non-magnetic (annealed) |
| PREN (approx.) | ≈ 35 |
SS 904L Equivalent Grades
SS 904L Sheet Weight Chart & Calculator
Use this to budget freight and price per piece. Weight (kg) = length (m) × width (m) × thickness (mm) × 7.95.
Example: 2500 × 1250 × 2 mm
2.5 × 1.25 × 2 × 7.95 = 49.7 kg
Total weight —
| Thickness | 2500 × 1250 sheet | Per m² |
|---|---|---|
| 0.5 mm | 12.4 kg | 4.0 kg |
| 0.8 mm | 19.9 kg | 6.4 kg |
| 1 mm | 24.8 kg | 8.0 kg |
| 1.2 mm | 29.8 kg | 9.5 kg |
| 1.5 mm | 37.3 kg | 11.9 kg |
| 2 mm | 49.7 kg | 15.9 kg |
| 3 mm | 74.5 kg | 23.9 kg |
| 4 mm | 99.4 kg | 31.8 kg |
SS 904L sheet gauge to mm
Gauge numbers are still common on drawings. Weights below use the density of SS 904L, 7.95 g/cm³.
Full chart: SWG sheet gauge chart.
| SWG | mm | inch | kg/m² (ρ 7.95) |
|---|---|---|---|
| 10 | 3.251 | 0.1280 | 25.85 |
| 11 | 2.946 | 0.1160 | 23.42 |
| 12 | 2.642 | 0.1040 | 21.00 |
| 14 | 2.032 | 0.0800 | 16.15 |
| 16 | 1.626 | 0.0640 | 12.93 |
| 18 | 1.219 | 0.0480 | 9.69 |
| 20 | 0.914 | 0.0360 | 7.27 |
| 22 | 0.711 | 0.0280 | 5.65 |
| 24 | 0.559 | 0.0220 | 4.44 |
Six-digit Harmonized System heading (iron and steel, chapter 72–73). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify SS 904L Sheet with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. SS 904L is most often mixed up with Inconel 825 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen; those come from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | SS 904L | Inconel 825 |
|---|---|---|
| Nickel | As specified | As specified |
| Chromium | As specified | As specified |
| Molybdenum | As specified | As specified |
| Copper | As specified | As specified |
| Titanium | — | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
SS 904L Sheet Price — What Decides It
Two quotes for "904L sheet" can differ by 20% and both be fair. We quote 904L sheet per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
SS 904L Sheet Tolerances, Edge & Flatness
Thickness, width, length and flatness tolerances for 904L sheet come from ASTM A480, the general-requirements standard called up by the product specification. Most quality problems with sheet are about these four, not the chemistry.
| Thickness tolerance | Per ASTM A480 tables, by thickness and width; ask for a tighter range on the PO if your press tooling needs it |
|---|---|
| Edge | Mill edge, or slit / cut edge for an exact width |
| Flatness | Standard flatness per ASTM A480; specify levelled or tension-levelled sheet where flatness is critical |
| Surface protection | PVC / PE film on bright and polished finishes; use laser-grade film if the sheet will be laser cut |
| Marking | Grade, heat number and standard on each sheet, or on each bundle for small pieces |
Sheet, Strip, Plate or Coil?
Under ASTM A480, flat material below 3/16" (4.76 mm) and 24" or wider is sheet; cold-rolled material narrower than 24" is strip; 3/16" (4.76 mm) and over it is plate (the metric edition, A480M, rounds these to 5 mm and 600 mm). Coil is the same product wound up for continuous processing — order coil if you will slit, blank or roll-form it yourself.
SS 904L Sheet Applications
Sheet goes where 904L has to be formed, pressed or used as a thin lining. For heavy shells, tube sheets and machined parts, see SS 904L plate.
How your 904L sheet order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI before processing is available on request.
- 03Processing — cutting to your sizes, with heat numbers transferred to every piece.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Forming & Welding SS 904L Sheet
Thin sheet is formed, folded and welded with little margin for heat. These are the points fabricators ask us about — matching filler for 904L is ER385 (AWS A5.9).
General guidance only; follow your approved WPS and forming procedure.
| Bending | Annealed austenitic sheet bends to tight radii but springs back more than carbon steel; over-bend slightly. |
|---|---|
| Work hardening | Heavy cold work raises hardness; your code may call for re-annealing after severe forming. |
| Thin-gauge welding | TIG (GTAW) with low heat input; argon back-purge the root to stop oxidation. |
| Distortion | Clamp to copper backing bars and stitch-tack before full welds. |
| Clean-up | Remove heat tint by pickling or passivation; keep carbon-steel tools and grinding dust away. |
How to Order SS 904L Sheet: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Standard and edition — e.g. ASTM A240-latest
- Thickness × width × length, and number of pieces
- Finish (2B, BA, No.4…) and protective film if needed
- Certificate type — 3.1 or 3.2, and the inspection agency
- Extra tests — UT, intergranular corrosion
- Delivery port, Incoterm and required date
SS 904L sheet for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 904L sheet — questions buyers ask
Is SS 904L the same as Alloy 904L?
Alloy 904L, UNS N08904, W.Nr 1.4539 are names used for SS 904L (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order), and sheet is ordered to ASTM A240 whichever name is on the enquiry.
What is the price of SS 904L sheet per kg?
It moves with nickel on the LME, so a fixed list price is out of date within days. Thickness, cut size, quantity and documents also change it. Send your size and quantity and we quote the same working day.
What documents come with an export shipment?
An EN 10204 3.1 mill certificate (or 3.2 with a third-party inspector), commercial invoice, packing list with heat numbers, and certificate of origin. Test reports are added for any extra tests ordered.
Which finish should I order for SS 904L sheet?
2B, unless the drawing says otherwise. Order BA for a mirror-like surface, No.4 for a brushed look and 2D for deep drawing.
Is SS 904L sheet ordered by gauge or by millimetre?
ASTM A240 uses millimetres or inches. Gauge numbers still appear on older drawings; the gauge-to-mm table on this page converts them, with 7.95 g/cm³ weights for 904L.
Can I order SS 904L sheet cut to size?
Yes. Send finished sizes and quantities, or a drawing; we quote cut pieces as well as full sheets. Tell us if edges must be deburred or protected.
Sheet, strip or coil — which should I order?
Sheet if you need flat pieces below 3/16" (4.76 mm) and at least 24" wide; strip if narrower; coil if you will slit, blank or roll-form the material on your own line.
What is the minimum order for sheet?
There is no fixed minimum for stock sizes — single sheets and cut pieces are quoted. Mill orders for a non-stock thickness or finish carry the mill minimum.
SS 904L or Inconel 825 — which should I choose?
SS 904L is chosen for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. Inconel 825 is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026