SS 304L — Sheet, Plate, Coil, Pipe & Tube & Fittings
Also sold as AISI 304L · UNS S30403 · W.Nr 1.4307 · Low-carbon 304
SS 304L is a low-carbon austenitic chromium-nickel stainless steel, chosen for welded tanks, piping and vessels in general corrosive service. We supply it as sheet, plate, coil, pipe & tube, fittings, flanges, fasteners, with EN 10204 3.1 certificates, from Mumbai to India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- UNS S30403
- W.Nr 1.4307
- PREN ≈ 18
- ρ 8 g/cm³
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
SS 304L Names, Designations & Composition
SS 304L is one alloy sold under several names. Its UNS number is S30403, the European material number is W.Nr 1.4307 and the EN name is X2CrNi18-9. The chart on the right shows the specified range of each main alloying element; the balance is the base metal.
SS 304L Specifications by Product — Which Standard Applies?
The material standard changes with the product form. This is the table buyers ask for most.
| Product | Material standard | Dimensions |
|---|---|---|
| SS 304L sheet | ASTM A240 | ASTM A480 / B906 |
| SS 304L plate | ASTM A240 | ASTM A480 / B906 / A20 |
| SS 304L coil | ASTM A240 | ASTM A480 |
| SS 304L pipe & tube | ASTM A312 TP304L · ASTM A312 · A358 | ASME B36.19 / B36.10 |
| SS 304L fittings | ASTM A403 WP304L · ASTM A182 F304L | ASME B16.9 · B16.11 |
| SS 304L flanges | ASTM A182 F304L | ASME B16.5 · B16.47 |
| SS 304L fasteners | ASTM A193 B8 · A194 8 | ASME B18.2.1 · B18.2.2 |
SS 304L Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | 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 S30403.
SS 304L 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 S30403 — Annealed plate & sheet.
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
SS 304L Corrosion Resistance — What Each Element Does
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.
The low carbon of the L grade 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.
SS 304L vs 304, 316L and 2205
| Grade | PREN (approx.) | Pick it for |
|---|---|---|
| SS 304 | ≈ 18 | General corrosion resistance, food, water and architectural work |
| SS 304L | ≈ 18 | Welded tanks, piping and vessels in general corrosive service |
| SS 316 / 316L | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| Duplex 2205 | ≈ 35 | Strength with chloride resistance at a stainless-steel budget |
Welding SS 304L
| Matching filler | ER308L (AWS A5.9) |
|---|---|
| Also used | ER309L for dissimilar joints |
SS 304L for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 304L — questions buyers ask
What is SS 304L?
SS 304L is a low-carbon austenitic chromium-nickel stainless steel. It is chosen for welded tanks, piping and vessels in general corrosive service.
Which standards cover SS 304L products?
Sheet: ASTM A240; Plate: ASTM A240; Coil: ASTM A240; Pipe & Tube: ASTM A312 TP304L · ASTM A312 · A358; Fittings: ASTM A403 WP304L · ASTM A182 F304L; Flanges: ASTM A182 F304L; Fasteners: ASTM A193 B8 · A194 8. Always name the standard and edition on your order.
What is the UNS number of SS 304L?
UNS S30403, with the European material number W.Nr 1.4307.
What is the density of SS 304L?
8 g/cm³ — use it to calculate weights: plate kg = L(m) × W(m) × t(mm) × 8.
SS 304L or Duplex 2205?
SS 304L suits welded tanks, piping and vessels in general corrosive service; Duplex 2205 is the step up for strength with chloride resistance at a stainless-steel budget.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026