SS 304 Pipe & TubeASTM A312 TP304 · Manufacturer, stockist & exporter, India
Also sold as AISI 304 · UNS S30400 · W.Nr 1.4301 · 18/8 stainless
SS 304 pipe is supplied seamless to ASTM A312 TP304 and welded to ASTM A312 · A358, in ASME pipe sizes and schedules, with tube to ASTM A213 · A269 · A249. It is a austenitic chromium-nickel stainless steel, chosen for general corrosion resistance, food, water and architectural work. 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 304 Pipe & Tube?
SS 304 pipe & tube is an austenitic chromium-nickel stainless steel supplied as pipe & tube to ASTM A312 TP304 (UNS S30400). Buyers specify it for general corrosion resistance, food, water and architectural work. It is also sold as AISI 304, UNS S30400, W.Nr 1.4301.
- What it is
- Austenitic chromium-nickel stainless steel
- Seamless
- ASTM A312 TP304
- Welded
- ASTM A312 · A358
- Sizes
- NPS ⅛" – 24" · OD tube to order
- Schedules
- 5S · 10S · 40S · 80S · 160 · XXS
- Best at
- General corrosion resistance, food, water and architectural work
SS 304 Pipe & Tube Specification & Sizes
| Seamless pipe | ASTM A312 TP304 |
|---|---|
| Welded pipe | ASTM A312 · A358 |
| Tube | ASTM A213 · A269 · A249 |
| Grade | SS 304 · UNS S30400 · W.Nr 1.4301 |
| Size & schedule | NPS ⅛" to 24" to ASME B36.19 / B36.10; OD × wall for tube |
| Length | Single random, double random, or cut lengths |
| Ends | Plain end · bevelled end (for welding) · threaded |
| Testing | Hydrostatic or eddy-current · PMI · flattening & flaring · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
SS 304 Pipe: Seamless, Welded or Tube?
Three different specifications cover 304 tubular products. Pick the route first — it decides price, test requirements and lead time. General requirements (tolerances, hydrostatic or electric testing) come from ASTM A999. Schedules, the −12.5% wall tolerance and the B31.3 wall formula are explained in the pipe guide.
| Route | Specification | Use it for |
|---|---|---|
| Seamless pipe | ASTM A312 TP304 | Pressure and critical service; no weld seam to inspect. |
| Welded pipe | ASTM A312 · A358 | Economical in larger diameters and thinner walls where the code allows it. |
| Tube | ASTM A213 · A269 · A249 | Heat exchangers and instruments; ordered by exact OD × wall. |
SS 304 Pipe Wall & Weight by Schedule
For the same size, the schedule sets the wall — and the weight you pay for. Cross-sections are drawn to scale for 2" NPS (OD 60.33 mm, ASME B36.19); weights use the density of SS 304, 8 g/cm³.
Other sizes: pipe schedule chart and weight calculator.
SS 304 Pipe & Tube 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 S30400.
SS 304 Pipe & Tube 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 S30400 — Annealed plate & sheet.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8 g/cm³ |
| Melting range | 1400 – 1450 °C |
| Magnetic | Non-magnetic annealed; slightly magnetic after cold work |
| PREN (approx.) | ≈ 18 |
SS 304 Equivalent Grades
SS 304 Pipe Weight Chart (kg/m)
Weight per metre (kg/m) = (OD − WT) × WT × 0.02513, with OD and wall thickness in mm. The factor comes from SS 304's density of 8 g/cm³.
Example: 4" Sch 40S (114.30 × 6.02 mm)
(114.30 − 6.02) × 6.02 × 0.02513 = 16.38 kg/m
| NPS | OD mm | Sch 10S kg/m | Sch 40S kg/m |
|---|---|---|---|
| ½" | 21.34 | 1.02 | 1.29 |
| 1" | 33.40 | 2.13 | 2.55 |
| 2" | 60.33 | 4.01 | 5.54 |
| 3" | 88.90 | 6.58 | 11.51 |
| 4" | 114.30 | 8.53 | 16.38 |
| 6" | 168.28 | 14.09 | 28.80 |
| 8" | 219.08 | 20.35 | 43.36 |
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 304 Pipe & Tube 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 304 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; 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 304 | SS 316 / 316L |
|---|---|---|
| Nickel | As specified | As specified |
| Chromium | As specified | As specified |
| Molybdenum | — | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
SS 304 Pipe & Tube Price — What Decides It
Two quotes for "304 pipe & tube" can differ by 20% and both be fair. We quote 304 pipe & tube 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 304 Pipe & Tube Applications
SS 304 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 304 Pipe & Tube vs 316L, 304L and 904L
| Grade | Pipe & Tube standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| SS 304L | ASTM A312 TP304L | ≈ 18 | Welded tanks, piping and vessels in general corrosive service |
| SS 304 | ASTM A312 TP304 | ≈ 18 | General corrosion resistance, food, water and architectural work |
| SS 316 / 316L | ASTM A312 TP316L | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 904L | ASTM A312 (N08904) | ≈ 35 | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
SS 304 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 304 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.
Standard carbon level: fine for most work, but choose 304L where heavy sections are welded and service is corrosive.
Without molybdenum, 304 pits in chlorides — step up to 316L for coastal or salty service.
How your 304 pipe & tube 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, 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.
Standards on this page
Welding & Fabricating SS 304 Pipe & Tube
SS 304 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ER308 / ER308L (AWS A5.9) |
|---|---|
| Over-alloyed filler | ER309L for dissimilar joints to carbon steel |
| 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 304 fittings and 304 flanges for the matching pipe-system parts.
How to Order SS 304 Pipe & Tube: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Seamless or welded, and the standard
- NPS and schedule (or OD × wall for tube)
- Length — random or cut, and number of lengths
- End finish — plain, bevelled or threaded
- Certificate type and extra tests
- Delivery port, Incoterm and required date
SS 304 pipe & tube for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 304 pipe & tube — questions buyers ask
Is SS 304 the same as AISI 304?
AISI 304, UNS S30400, W.Nr 1.4301 are names used for SS 304 (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 pipe & tube is ordered to ASTM A312 TP304 whichever name is on the enquiry.
What is the difference between SS 304 pipe and tube?
Pipe is ordered by nominal pipe size and schedule, for carrying fluids. Tube is ordered by exact outside diameter and wall, for heat exchangers and instruments, and is held to tighter tolerances.
Seamless or welded SS 304 pipe — which should I buy?
Seamless (ASTM A312 TP304) is the default for pressure and critical service. Welded (ASTM A312 · A358) is cheaper in larger diameters and thinner walls and is accepted where the design code allows it.
What is the wall-thickness tolerance on SS 304 pipe?
Seamless pipe is normally allowed −12.5% on nominal wall under its general-requirements standard (ASTM A999). Allow for it in the pressure calculation or order on minimum wall.
Can SS 304 pipe be welded to carbon-steel pipe?
Yes, with the right filler: ER309L (or E309L electrode) is the usual filler when joining it to carbon steel. Follow a qualified WPS.
SS 304 or SS 904L — which should I choose?
SS 304 is chosen for general corrosion resistance, food, water and architectural work. SS 904L 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