SS 304L CoilASTM A240 UNS S30403 · Manufacturer, stockist & exporter, India
Also sold as AISI 304L · UNS S30403 · W.Nr 1.4307 · Low-carbon 304
SS 304L coil is supplied as full-width mother coil, slit coil or precision strip to ASTM A240. It is a low-carbon austenitic chromium-nickel stainless steel, chosen for welded tanks, piping and vessels in general corrosive service. 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 every heat
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is SS 304L Coil?
SS 304L coil is a low-carbon austenitic chromium-nickel stainless steel supplied as coil to ASTM A240 (UNS S30403). Buyers specify it for welded tanks, piping and vessels in general corrosive service. It is also sold as AISI 304L, UNS S30403, W.Nr 1.4307.
- What it is
- Low-carbon austenitic chromium-nickel stainless steel
- Standard
- ASTM A240
- Forms
- Mother coil · slit coil · strip
- Density
- 8 g/cm³
- Finish
- 2B · BA · No.4
- Best at
- Welded tanks, piping and vessels in general corrosive service
SS 304L Coil Specification & Sizes
| Material standard | ASTM A240 |
|---|---|
| Grade | SS 304L |
| Thickness | 0.1 mm to 6 mm, depending on mill route |
| Width | Mill width, or slit from 10 mm upwards |
| Coil weight & ID | To order — state maximum coil weight and inner diameter |
| Finish | 2B · BA · No.4 · 2D |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
SS 304L Coil: Slitting & Cut-to-Length Specification
304L coil is bought for a production line, so state thickness, slit width, inner diameter and maximum coil weight with the grade.
| Standard | ASTM A240 |
|---|---|
| Thickness tolerance | Per ASTM A480 |
| Finish | 2B · BA · No.4 · 2D |
ID, coil weight, edge, camber and interleaving: see the coil guide.
SS 304L Coil Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 17.5 – 19.5 |
| Nickel | 8.0 – 12.0 |
| Carbon | 0.030 max |
| Manganese | 2.00 max |
| Silicon | 0.75 max |
| Nitrogen | 0.10 max |
| Phosphorus | 0.045 max |
| Sulphur | 0.030 max |
| Iron | Balance |
SS 304L Coil Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 485 MPa · 70 ksi |
| Yield strength 0.2% | 170 MPa · 25 ksi |
| Elongation | 40% |
| Hardness | 201 HB max |
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8 g/cm³ |
| Melting range | 1400 – 1450 °C |
| Magnetic | Non-magnetic annealed |
| PREN (approx.) | ≈ 18 |
SS 304L Equivalent Grades
Values follow ASTM A240 for UNS S30403. Always check against the edition named on your purchase order.
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 304L Coil 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 304L is most often mixed up with SS 316 / 316L — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen, so it cannot tell 304 from 304L: the low carbon is confirmed by the mill certificate or optical emission (OES) testing. We PMI-test nickel alloys as standard and any grade on request.
| Element | SS 304L | SS 316 / 316L |
|---|---|---|
| Nickel | 8.0 – 12.0 | 10.0 – 14.0 |
| Chromium | 17.5 – 19.5 | 16.0 – 18.0 |
| Molybdenum | residual | 2.00 – 3.00 |
| Iron | Balance | Balance |
| Manganese | 2.00 max | 2.00 max |
SS 304L Coil Applications
SS 304L is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
SS 304L Coil vs 304, 316L and 2205
| Grade | Coil standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| SS 304 | ASTM A240 | ≈ 18 | General corrosion resistance, food, water and architectural work |
| SS 304L | ASTM A240 | ≈ 18 | Welded tanks, piping and vessels in general corrosive service |
| SS 316 / 316L | ASTM A240 | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| Duplex 2205 | ASTM A240 | ≈ 35 | Strength with chloride resistance at a stainless-steel budget |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
SS 304L Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether 304L fits.
About 18% chromium forms the passive film that makes the steel stainless.
Nickel keeps the structure austenitic — tough at low temperature and easy to form and weld.
0.030% carbon max stops carbide forming at grain boundaries during welding, so heavy welds keep their corrosion resistance.
Most mill material today is dual-certified 304/304L, meeting the strength of 304 and the carbon limit of 304L.
How your 304L coil order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked and material is PMI-tested before processing.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 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.
Welding & Fabricating SS 304L Coil
SS 304L welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ER308L (AWS A5.9) |
|---|---|
| Over-alloyed filler | ER309L for dissimilar joints |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also 304L fittings and 304L flanges for the matching pipe-system parts.
How to Order SS 304L Coil: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Thickness and width
- Coil weight and inner diameter
- Finish and edge (mill or slit)
- Certificate type
- Delivery port and date
SS 304L coil for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 304L coil — questions buyers ask
Is SS 304L the same as AISI 304L?
Yes. AISI 304L, UNS S30403, W.Nr 1.4307 all refer to the same material, and coil is ordered to ASTM A240 whichever name is on the enquiry.
Can SS 304L coil be slit to width?
Yes. Coils can be slit to narrow widths for stamping, tube making and spring work; state width tolerance and coil weight on the enquiry.
What inner diameter do SS 304L coils have?
508 mm (20") and 610 mm (24") are the common IDs. Tell us your decoiler ID and maximum coil weight and we slit to suit.
Can I order SS 304L cut-to-length sheets from coil?
Yes. Coil can be levelled and cut to length; state length tolerance and flatness.
SS 304L or Duplex 2205 — which should I choose?
SS 304L is chosen for welded tanks, piping and vessels in general corrosive service. Duplex 2205 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