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SS 304 Seamless Pipe
Seamless 304 pipe begins life as a solid billet. Piercing over a mandrel and drawing to size leaves no longitudinal weld, so refinery transfer lines specify it wherever cyclic loading would work against a seam.
Stainless Steel 304 Pipe Manufacturer in India
MLTI Private Limited (Moonlight Tube Industries) has been manufacturing Stainless Steel 304 Pipe in Gujarat since 2008 and has a combined annual production capacity of nearly 8,000 MT. We produce to ASTM A312 / ASME SA-312 in grade TP304, carrying the UNS S30400 designation.
Grade 304 is the 18/8 austenitic composition at the base of the chromium-nickel family: 18.0 to 20.0% chromium against 8.0 to 11.0% nickel, carbon capped at 0.08%. Chromium builds the passive oxide film that holds off oxidising acids, while nickel holds the austenite phase stable well below zero, so the pipe keeps its toughness at cryogenic temperatures. SA-312 sets minima of 515 MPa tensile, 205 MPa yield, and 35% elongation. We produce 1/8" NB through 10" NB across SCH 5S, 10S, 20S, 40S, and 80S. Round sections follow B36.19; square and rectangular sections are supplied as welded stainless mechanical tubes to ASTM A554. ASTM A312 opens two routes to this grade: seamless and welded. ERW is a welded route, and it is the one this mill was built around. Seamless 304 pipe and welded pipe each serve the same grade through different manufacturing routes. Chemical process lines, dairy installations, and instrumentation runs take most of our dispatch.
Every length leaves the solution annealed at 1040°C minimum, proved by a hydrostatic or nondestructive electric test to A999/A999M, and documented on an EN 10204 3.1 certificate. We hold ISO 14001 and ISO 45001 certifications alongside BIS, EIL, IBR, and PED 2014/68/EU approvals.
Stainless Steel 304 Pipe Specifications
The table below sets out the ordering variables for SS 304 pipe: applicable and dimensional standards, size range, schedule, wall thickness, length, manufacturing form, section profile, finish, and end type.
| Parameter | Value |
|---|---|
| Applicable Standard | ASTM A312 / ASME SA-312: Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes |
| Dimensional standard | ASME B36.19 for outside diameter and for SCH 5S, 10S, 40S and 80S walls; SCH 20S walls to MLTI standard, outside B36.19 |
| Size range | 1/8" NB to 10" NB |
| Schedule | SCH 5S, SCH 10S, SCH 20S, SCH 40S, SCH 80S |
| Wall thickness | 1.24 mm to 12.70 mm, by bore and schedule |
| Length | 3 m and 6 m as standard, with cut lengths to order. ASTM A312 regular practice for 1/8" to 8" NB is a maximum of 24 ft (7.32 m), within a 15 ft to 24 ft range. |
| Manufacturing form | Seamless (SML) and welded (WLD) to ASTM A312; ERW is our welded route |
| Section profile | Round to ASTM A312 / ASME B36.19; square and rectangular to ASTM A554 |
| Finish | Mill-finished, solution-annealed and pickled |
| End type | Plain end; bevelled to order. Threading to ASME B1.20.1 on SCH 40S and SCH 80S only, since SCH 5S and SCH 10S walls do not permit it. |
SS 304 Pipe Chemical Composition
Chromium and nickel set the corrosion and phase behaviour of grade 304, with carbon, manganese, silicon, phosphorus, and sulphur held to fixed ceilings. No stabilising element enters the composition. The table below sets out element limits for UNS S30400 pipe against the SA-312 requirement.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 max |
| Manganese (Mn) | 2.00 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.030 max |
| Silicon (Si) | 1.00 max |
| Chromium (Cr) | 18.0 to 20.0 |
| Nickel (Ni) | 8.0 to 11.0 |
| Iron (Fe) | Balance |
The 0.08% carbon ceiling separates 304 from its low-carbon variant. Free carbon combines with chromium at grain boundaries between 425°C and 815°C. Light welding cycles rarely reach that exposure, though heavy multi-pass work on 6" and 8" bores does.
304 SS Pipe Mechanical Properties
ASTM A312 / ASME SA-312 sets four tensile values for TP304, every one a specified minimum. A mill certificate reporting tested values above them is conforming.
| Property | Requirement |
|---|---|
| Tensile strength, min | 515 MPa (75 ksi) |
| Yield strength, min | 205 MPa (30 ksi) |
| Elongation in 50 mm, min, longitudinal | 35% |
| Elongation in 50 mm, min, transverse | 25% |
ASTM A312 TP304 requires no wall-thickness strength reduction, so 515 MPa applies at the lightest schedule and the heaviest equally.
Equivalent Grades and Designations for 304 Pipe
Export orders on a European or Japanese specification need a cross-reference. Designations for UNS S30400 pipe appear in the table below.
| Standard | Designation |
|---|---|
| UNS (USA) | S30400 |
| EN / Werkstoff (Europe) | 1.4301 / X5CrNi18-10 |
| JIS (Japan) | SUS304TP |
| IS (India) | X04Cr19Ni9 |
| GB (China) | 06Cr19Ni10 |
UNS S30400 Pipe and TP304: What the Designations Mean
Two codes travel with every mill certificate. UNS S30400 identifies the alloy itself, independent of product form, and holds across plate, bar, and pipe. TP304 is the SA-312 grade symbol tied to the pipe specification. A certificate naming UNS S30400 pipe without a TP304 line gives the alloy, not the standard.
Stainless Steel 304 Pipes: Forms and Types
Two questions settle the order on this grade. Seamless or welded describes how the pipe is formed; round, square or rectangular describes the finished section.
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SS 304 Welded Pipe (ERW)
Welded 304 pipe is formed from annealed strip and closed along its length. Our ERW line resistance welds that seam without filler metal. Because the pipe is formed from a cold-rolled strip of even gauge, wall variation around the circumference stays low. Across the bores on this page, A312 Table 3 applies one tolerance band to welded and seamless alike, except that the weld area itself is not limited by the over-tolerance.
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304 Stainless Steel Round Pipe
The round section takes the bulk of our output. A circular bore spreads hoop stress evenly, so process piping and headers are round.
Square
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304 Stainless Steel Square Pipe
304 stainless steel square pipe is used mainly for structural work rather than pressure service. Its flat faces make it easy to bolt and butt-weld against plate, and it is commonly used for handrails, frames, and similar box-profile applications.
Rectangular
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Rectangular 304 Pipe
Rectangular 304 pipe is also used for structural work instead of pressure service. The flat faces make it suitable for bolting and butt-welding against plate, and it is often chosen for handrails, frames, and other box-profile structures.
Stainless Steel 304 Pipe Sizes
We roll 304 stainless steel pipe across sixteen bores and five schedules. Outside diameters follow ASME B36.19. Schedule 20S walls and Schedule 5S walls at 1/8", 1/4", and 3/8" are not listed in ASME B36.19 and are supplied to MLTI's own wall schedule.
| Nominal Bore (mm) | Nominal Bore (INCH) | Outside Diameter (mm) | Sch-5S Thickness (mm) | Sch-10S Thickness (mm) | Sch-20S Thickness (mm) | Sch-40S Thickness (mm) | Sch-80S Thickness (mm) |
|---|---|---|---|---|---|---|---|
| 6 | 1/8 | 10.30 | 1.24 | 1.50 | 1.73 | 2.41 | |
| 8 | 1/4 | 13.70 | 1.65 | 2.00 | 2.24 | 3.02 | |
| 10 | 3/8 | 17.10 | 1.65 | 2.00 | 2.31 | 3.2 | |
| 15 | 1/2 | 21.34 | 1.65 | 2.11 | 2.30 | 2.77 | 3.75 |
| 20 | 3/4 | 26.70 | 1.65 | 2.11 | 2.55 | 2.87 | 3.91 |
| 25 | 1 | 33.40 | 1.65 | 2.77 | 3.00 | 3.38 | 4.55 |
| 32 | 1 1/4 | 42.20 | 1.65 | 2.77 | 3.00 | 3.56 | 4.85 |
| 40 | 1 1/2 | 48.30 | 1.65 | 2.77 | 3.00 | 3.68 | 5.08 |
| 50 | 2 | 60.30 | 1.65 | 2.77 | 3.00 | 3.91 | 5.54 |
| 65 | 2 1/2 | 73 | 2.11 | 3.05 | 4.00 | 5.16 | 7.01 |
| 80 | 3 | 88.9 | 2.11 | 3.05 | 4.00 | 5.49 | 7.62 |
| 100 | 4 | 114.3 | 2.11 | 3.05 | 4.50 | 6.02 | 8.56 |
| 125 | 5 | 141.3 | 2.77 | 3.4 | 5.00 | 6.55 | 9.53 |
| 150 | 6 | 168.3 | 2.77 | 3.4 | 6.35 | 7.11 | 10.97 |
| 200 | 8 | 219.1 | 2.77 | 3.76 | 6.35 | 8.18 | 12.7 |
| 250 | 10 | 273.1 | 3.4 | 4.19 | 6.35 | 9.27 | 12.7 |
304 Pipe Schedule and Wall Thickness Chart
Schedule fixes wall rather than bore, and the same schedule number thickens as NB climbs: SCH 40S measures 2.77 mm at 1/2" against 8.18 mm at 8".
Stainless Steel 304 Pipe Weight per Meter
Weight follows from the outside diameter, wall, and a density of 7.85 g/cm³. Figures below are calculated, not certified, and a mill certificate governs the delivered mass.
| Nominal Bore (mm) | Nominal Bore (INCH) | Sch-5S Weight (Kg/mt) | Sch-10S Weight (Kg/mt) | Sch-20S Weight (Kg/mt) | Sch-40S Weight (Kg/mt) | Sch-80S Weight (Kg/mt) |
|---|---|---|---|---|---|---|
| 6 | 1/8 | 0.28 | 0.33 | 0.37 | 0.47 | |
| 8 | 1/4 | 0.49 | 0.58 | 0.631 | 0.8 | |
| 10 | 3/8 | 0.63 | 0.74 | 0.845 | 1.1 | |
| 15 | 1/2 | 0.8 | 1 | 1.08 | 1.27 | 1.62 |
| 20 | 3/4 | 1.03 | 1.28 | 1.52 | 1.68 | 2.2 |
| 25 | 1 | 1.3 | 2.09 | 1.94 | 2.5 | 3.24 |
| 32 | 1 1/4 | 1.65 | 2.7 | 2.90 | 3.38 | 4.47 |
| 40 | 1 1/2 | 1.91 | 3.11 | 3.35 | 4.05 | 5.41 |
| 50 | 2 | 2.4 | 3.93 | 4.24 | 5.44 | 7.48 |
| 65 | 2 1/2 | 3.69 | 5.26 | 6.81 | 8.63 | 11.4 |
| 80 | 3 | 4.51 | 6.45 | 8.37 | 11.3 | 15.2 |
| 100 | 4 | 5.84 | 8.36 | 12.18 | 16.07 | 22.3 |
| 125 | 5 | 9.47 | 11.57 | 16.81 | 21.8 | 31.97 |
| 150 | 6 | 11.32 | 13.84 | 25.36 | 28.3 | 42.7 |
| 200 | 8 | 14.79 | 19.96 | 33.31 | 42.6 | 64.6 |
| 250 | 10 | 22.63 | 27.78 | 41.77 | 60.5 | 96 |
Standard Lengths
Stock ranges from 3 m to 6 m, with 20 ft and 10 ft cuts for imperial orders. Cutting happens in-house, and we will hold any length up to 24 ft (7.32 m), which is the regular-practice maximum ASTM A312 sets for 1/8" to 8" NB
Stainless Steel 304 Pipe Industrial Applications
Six sectors use the 304 stainless steel pipe leaving our works, each for a different reason.
Chemical Process Industry
Nitric acid, organic acids, and alkaline liquors move through 304 pipes in reactor feed lines and transfer headers. The passive chromium film holds against oxidising media.
Food and Beverage Processing
Dairy plants, breweries, and edible-oil refineries run 304 pipe on product-contact duty. A pickled surface leaves nothing for residue to key into, and routine caustic clean-in-place cycles leave it intact. Chlorinated cleaning agents are the one thing to keep off it, since chlorides pit 304 where plain caustic does not.
Oil and Gas
Utility and instrument piping uses 304 wherever the medium stays sweet across platforms and refineries. Sour service with hydrogen sulphide does not qualify.
Power Generation
Condensate lines, feedwater headers and ash-handling runs take 304 pipe in thermal stations, where it welds into existing austenitic circuits without a filler change.
Instrumentation and Hydraulic Lines
Small-bore 304 pipe carries impulse lines and sample loops at 3/8" and 1/2" NB, joined by socket-weld or threaded fittings. Where the run calls for compression fittings, the correct product is 304 tubing to ASTM A269, ordered on actual outside diameter rather than nominal bore.
Structural and Architectural
Handrail, balustrade and canopy frames use square and rectangular 304 sections, and inland exposure leaves the surface intact for decades.
Stainless Steel 304 Pipe Shipping and Packaging
Stainless Steel 304 pipes are shipped in bundles and packaged to protect them during transit. End caps and PVC sleeving are used where required, and each length is marked with the relevant details. Test certificates are sent with the shipment.
- Pipe leaves the works banded into bundles sorted by schedule, then timber-cased where the destination requires it.
- End protection uses push-fit caps; PVC sleeving is applied when the order calls for it.
- Each length is stencilled with heat number, grade, specification and schedule.
- Test certification to EN 10204 3.1 travels with the consignment and is emailed at despatch.
304 Stainless Steel Pipe Price
Pricing on 304 pipe ranges from ₹250–₹325 per kg and US$2.63–$3.42 per kg. It moves with nickel on the LME and mill conversion rates, so we quote against the day rather than publish a list. Per-kilogram quoting suits project tonnage, while running-metre pricing suits fixed cutting schedules and mixed orders.
Why Buy Stainless Steel 304 Pipe From MLTI?
Buyers return to Moonlight Tubes for certified material, approved grades and stock that ships on schedule. Every order is backed by documented quality, a wide size range and delivery commitments we hold to.
Quality Certification
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IBR & EIL Approved
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Why
Choose Us
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Wide Range of Grades & Sizes
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Timely Global Delivery
Stainless Steel 304 Pipe: Frequently Asked Questions
304 pipe carries process fluids across four duties: chemical plants, dairy and brewing lines, condensate circuits and instrument impulse lines. A fifth, non-pressure use is structural: handrail, balustrade and canopy frames in square and rectangular sections.
The wall thickness ranges from 1.24 mm to 12.70 mm, set by bore and schedule. A 2" NB pipe measures 2.77 mm at SCH 10S against 5.54 mm at SCH 80S.
Our SS304 round pipe covers 1/8" NB to 10" NB in SCH 5S, 10S, 20S, 40S and 80S. Square and rectangular sections are supplied separately to ASTM A554, sized by outside diameter and gauge.
Price ranges from ₹250–₹325 per kg and US$2.63–$3.42 per kg. Rates quoted by the kilogram track nickel and mill conversion cost, so they shift week to week. A 2-inch line item is quoted on finished weight.
Weight follows outside diameter and wall: 1" SCH 40S runs 2.5 kg/m, and 4" SCH 40S runs 16.07 kg/m. The weight table above covers the full range at 7.85 g/cm³.
Both seamless and welded fall under ASTM A312 / ASME SA-312, so one specification certifies either. We supply seamless and ERW to A312. EFW is welded with filler metal, which places it under ASTM A358, and we certify it to that specification.
Pipe is ordered by nominal bore and schedule under ASME B36.19. Tubing goes by actual outside diameter and wall gauge, on a separate tolerance system.
You can buy SS 304 pipes from us at Moonlight Tube Industries. We are a trusted manufacturer of 304 SS pipes in India, with export cargo moving to Brazil, Vietnam, Turkey and Europe.