Chemical Processing
Chemical plants run process lines and the piping around chemical processing vessels in seamless 304L pipe, where site welds must resist intergranular attack from corrosive process media.
ASTM A312 / ASME SA-312 / UNS S30403 / W.Nr. 1.4307
Stainless Steel 304L Seamless Pipes Manufacturer in Thailand
Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. offers ASTM A312 TP304L stainless steel seamless pipes produced at its Ban Bueng, Chonburi plant in Thailand for welded process lines that go into service without a post-weld anneal. UNS S30403, designated WNR 1.4307 in Europe, holds carbon to 0.035% maximum, which reduces the risk of sensitization and intergranular corrosion after welding compared with standard 304. It is part of our stainless steel seamless pipes range, quoted from our office in Bang Phli, Samut Prakan.
Stainless Steel 304L seamless pipeUNS S30403 / W.Nr. 1.4307
- 6 to 1016 mmOutside diameter
- 1 to 65 mmWall thickness
- Up to 18 mLength
- EN 10204 3.1Test certificate
EN 10204 3.1 certificate / 3.2 on request
Specifications of ASTM A312 TP304L Stainless Steel Seamless Pipe
Specify each SS 304L seamless pipe as NPS with schedule, or as OD with wall thickness, inside the range below.
- Standard
- ASTM A312 / ASME SA-312
- Grade
- TP304L (UNS S30403)
- Outside Diameter
- 6 to 1016 mm
- Wall Thickness
- 1 to 65 mm
- Length
- Up to 18 mor cut to length
- Dimensions
- ASME B36.19M and B36.10M schedules, or OD and wall to drawing
- End Type
- Plain endbeveled end, threaded end (Sch 40S and heavier)
- Surface Finish
- Pickled and passivatedbright annealed, polished, mirror, brushed
- Form
- Seamless
- Manufacturing Route
- 1Hot piercing over a mandrel
- 2Hot rolling and cold drawing
- Heat Treatment
- Solution annealed at 1040 °C (1900 °F) minimum, water quenched or rapidly cooled
- Testing
- Hydrostatic or nondestructive electric test on every pipe
- Tension and flattening tests per lot
- Test Certificate
- EN 10204 3.13.2 on request
ASTM A312 / ASME SA-312 sets the requirements for austenitic grades in high-temperature and general corrosive service, and it requires seamless product to be made by a process with no welding at any stage of production. The A312 schedule tables follow ASME B36.19, and drawing-specific OD and wall combinations are permitted under the same specification. Every ASTM A312 stainless steel 304L seamless pipe we release is marked SML with its heat number. When your design is sized by OD and wall rather than NPS, the same grade is produced as 304L seamless tubes.
Every heat is covered by an EN 10204 3.1 (3.2 on request) material test certificate. Supporting records include the raw material certificate, positive material identification (PMI) results for each length, heat treatment charts, surface roughness and size measurements, and a laboratory test certificate from a government-approved lab. A third-party inspection report is available on request, and product analysis on finished pipe can be added when your specification calls for it.
Chemical Composition of UNS S30403 Seamless Pipe
Every UNS S30403 seamless pipe is made to the TP304L limits of ASTM A312, and each heat is reported against them on the mill test certificate. A312 sets no nitrogen or molybdenum limit for this grade.
- CrChromium, 18.0 to 20.0
- NiNickel, 8.0 to 13.0
- MnManganese, 2.00 max
- SiSilicon, 1.00 max
- PPhosphorus, 0.045 max
UNS S30403304L
| Element | TP304L Limit (%) |
|---|---|
| C (Carbon) | 0.035 max |
| Mn (Manganese) | 2.00 max |
| P (Phosphorus) | 0.045 max |
| S (Sulfur) | 0.030 max |
| Si (Silicon) | 1.00 max |
| Cr (Chromium) | 18.0 to 20.0 |
| Ni (Nickel) | 8.0 to 13.0 |
For small-diameter or thin-wall pipe that needs many drawing passes, A312 allows carbon up to 0.040% maximum. This applies to OD under 12.7 mm, or to wall under 1.20 mm average (1.10 mm minimum).
Mechanical Properties of TP304L Seamless Pipe
The TP304L minimums sit below those of TP304, so base the wall calculation for a SS 304L seamless pipe on the figures below. One pipe per lot of up to 100 pipes is tension tested, and two on larger lots.
| Property | Value | Unit |
|---|---|---|
| Tensile Strength, min | 485 (70) | MPa (ksi) |
| Yield Strength, min | 170 (25) | MPa (ksi) |
| Elongation in 2 in. or 50 mm, min, longitudinal | 35 | % |
| Elongation in 2 in. or 50 mm, min, transverse | 25 | % |
Flattening tests are run on 5% of each lot, and on no fewer than two lengths, when the pipe is annealed in a continuous furnace or direct quenched.
Equivalent Designations of Stainless Steel 304L
On drawings and data sheets from different countries, Stainless Steel 304L appears under the designations below.
- USA (ASTM / ASME)ASTM A312 / ASME SA-312 TP304L
- USA (UNS)UNS S30403
- USA (AISI)304L
- Europe (EN / WNR)WNR 1.4307
- ISOX2CrNi19-11
- Japan (JIS)SUS304L
- China (GB)S30403 (ISC) / 022Cr19Ni10
- Russia (GOST)03X18H11
- United Kingdom (BS)304S11
UNS S30403 is the designation stated on the mill certificate. When a European data sheet calls for seamless WNR 1.4307 pipe, we cross-reference 1.4307 on the same certificate.
Seamless Stainless Steel 304L Pipe Sizes and Tolerances
Our seamless stainless steel 304L pipe range runs from 6 mm to 1016 mm OD and 1 mm to 65 mm wall, with lengths to 18 m. Schedules 5S, 10S, 40S and 80S follow ASME B36.19M, and heavier ASME B36.10M schedules are made within the same wall range. Light and standard stainless schedules for welded process lines, nominal wall in mm per ASTM A312:
| NPS | OD (mm) | Sch 5S | Sch 10S | Sch 40S |
|---|---|---|---|---|
| 1/2 | 21.3 | 1.65 | 2.11 | 2.77 |
| 4 | 114.3 | 2.11 | 3.05 | 6.02 |
| 8 | 219.1 | 2.77 | 3.76 | 8.18 |
| 12 | 323.9 | 3.96 | 4.57 | 9.53 |
Swipe sideways to see the full table.
Wall Thickness Tolerance
Wall tolerance under A312 is a percentage of nominal wall that varies with NPS and with the wall-to-OD ratio (t/D). Ordering to minimum wall removes the under-tolerance.
| NPS | t/D | Wall Tolerance (% of nominal) |
|---|---|---|
| 1/8 to 2-1/2 | All | +20.0 / -12.5 |
| 3 to 18 | Up to 5% | +22.5 / -12.5 |
| 3 to 18 | Over 5% | +15.0 / -12.5 |
| 20 and larger | Up to 5% | +22.5 / -12.5 |
| 20 and larger | Over 5% | +15.0 / -12.5 |
Outside Diameter Tolerance
Permitted variations in outside diameter for our Stainless Steel 304L Seamless Pipes, as they apply to A312 pipe:
| NPS | DN | OD Tolerance (mm) | OD Tolerance (in.) |
|---|---|---|---|
| 1/8 to 1-1/2 | 6 to 40 | +0.4 / -0.8 | +1/64 / -1/32 |
| Over 1-1/2 to 4 | Over 40 to 100 | +0.8 / -0.8 | +1/32 / -1/32 |
| Over 4 to 8 | Over 100 to 200 | +1.6 / -0.8 | +1/16 / -1/32 |
| Over 8 to 18 | Over 200 to 450 | +2.4 / -0.8 | +3/32 / -1/32 |
| Over 18 to 26 | Over 450 to 650 | +3.2 / -0.8 | +1/8 / -1/32 |
| Over 26 to 34 | Over 650 to 850 | +4.0 / -0.8 | +5/32 / -1/32 |
| Over 34 to 48 | Over 850 to 1200 | +4.8 / -0.8 | +3/16 / -1/32 |
Swipe sideways to see the full table.
For thin-wall pipe (wall no more than 3% of OD), the tolerance is checked on the mean of the maximum and minimum OD readings in one cross-section, and the difference between those readings may not exceed 1.5% of the specified OD.
Lengths and Cut Lengths
Cut lengths are supplied with no under-length and up to 6 mm (1/4 in.) over. Jointers are excluded unless your order permits them.
Welding and Fabrication of Seamless WNR 1.4307 Pipe
Carbon is the difference that matters at the weld. TP304 allows up to 0.08% carbon, while TP304L is held to 0.035%, which limits carbide precipitation in the weld heat-affected zone. That makes seamless WNR 1.4307 pipe the preferred choice for heavy-section welded fabrications that will not receive post-weld annealing, and ER308L is the matching filler metal. In the non-sensitized condition, its corrosion resistance is essentially equal to that of 304. Before release, every length is solution annealed at 1040 °C (1900 °F) minimum and quenched in water or rapidly cooled to prevent carbide re-precipitation, which ASTM A262 Practice E can demonstrate on request.
304L or 304 for Welded Lines
Choose 304L for lines that stay in the as-welded condition. Where strength governs instead, 304 seamless pipes offer 515 MPa tensile and 205 MPa yield minimums against 485 MPa and 170 MPa for 304L. A single heat can be dual-certified to both grades when its chemistry and properties fall within both ranges.
When to Step Up to 316L
ASTM A312 sets no molybdenum requirement for TP304L. For chloride-bearing media, molybdenum-alloyed 316L seamless pipes add resistance to chloride pitting and crevice corrosion, so state the chloride content of your process stream when you inquire.
Industrial Applications of Seamless 1.4307 Stainless Steel Pipe
Seamless 1.4307 stainless steel pipe is specified where process piping is welded in place and has to keep its corrosion resistance at every joint.
Food and Beverage Processing
Product, cleaning and utility lines in food and beverage plants are welded in place, and the low carbon of TP304L limits sensitization at each fabricated joint along the line.
Pharmaceutical Process Piping
Pharmaceutical process and transfer lines take bright annealed or polished SS 304L seamless pipe, where the internal surface condition is written into the specification for cleaning and product purity.
Pulp and Paper Mills
Pulp and paper mills use 304L stainless steel seamless pipe for process and utility lines, with welded headers and branches fabricated on site during plant shutdowns and expansions.
Cryogenic Equipment
Cryogenic equipment rated down to -196 °C uses seamless stainless steel 304L pipe for transfer lines and vessel connections, where the welded piping must stay serviceable at very low temperature.
Shipping and Packaging of Seamless S30403 Stainless Steel Pipe
Bundling
Lengths strapped together and wrapped, sleeved in woven bags, or crated in wooden or plywood boxes for sea freight.
Mill marks on each length
NPS or OD, schedule or average wall, heat number, the SML seamless mark and our manufacturer's mark, with NH, ET or UT added where they apply.
Bore protection
A plastic cap on every plain or beveled end until the pipe reaches your site.
Your own marks
Stenciling, color codes or barcode labels as your project requires.
Cutting and bevels
Lengths cut and ends beveled to your line list before shipment.
Trade terms
FOB, CIF or CFR.
Paperwork with each seamless S30403 stainless steel pipe consignment: the EN 10204 3.1 (3.2 on request) material test certificate and heat treatment charts, plus a third-party inspection report on request.
SS 304L Seamless Pipe Price per kg
ASTM A312 stainless steel 304L seamless pipe is indicatively priced at around USD 2.75 to 5.5 per kg. The final price depends on NPS, schedule, length, finish, quantity and testing, and it moves with the nickel price. Send your line items to Thaida for a firm quotation.
Indicative price, Stainless Steel 304L Seamless Pipes
USD 2.75 to 5.5 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Schedule
- Length
- Finish
- Quantity
- Testing and certification
- Nickel price
Manufacturing and Export from Thailand
All our Stainless Steel 304L Seamless Pipes are pierced, rolled, drawn and annealed at our factory, 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Line-list reviews and export paperwork are prepared at our office, 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. Pipe leaves from stock or from a scheduled production run for sites in Thailand, Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Factory154 Moo.1 Map Phai, Ban Bueng,
Chonburi 20170, Thailand
Chonburi 20170, Thailand
Office89/18 Moo.15 Enterprize Park, Bangna-Trad Road,
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Exporting to
- Singapore
- Malaysia
- Vietnam
- Indonesia
- Philippines
- India
Seamless 304L Pipe FAQ
Does 304L seamless pipe need annealing after welding?
Usually not. With carbon held to 0.035% maximum, TP304L joints can stay in the as-welded condition in most process service, including heavy sections that cannot be re-annealed. When your specification asks for proof, add intergranular corrosion testing to ASTM A262 to the order.
What carbon limit applies to ASTM A312 TP304L seamless pipe?
0.035% maximum, under half the 0.08% that TP304 allows. The one exception is drawn small-bore or very thin-wall pipe, where A312 permits 0.040%. The actual carbon of each heat is printed on the mill test certificate, so you can check it against the value your welding procedure assumes.
Can one seamless pipe be certified to both 304 and 304L?
Yes, when the heat's chemistry and properties fall within both grades' ranges: carbon within the 0.035% limit of 304L, and tensile and yield strength at or above the higher TP304 minimums. Note it on the order when your line list names 304 but your welding plan needs 304L chemistry.
What hydrostatic test pressure is used for seamless 304L pipe?
The test stress is at least 50% of the specified minimum yield, which is 170 MPa for TP304L. Pressure need not exceed 17.0 MPa for OD up to 88.9 mm or 19.0 MPa above, held for at least 5 seconds. Each pipe gets a hydrostatic or nondestructive electric test, at our option unless your order specifies one.
What wall tolerance applies to 304L stainless steel seamless pipe?
It depends on NPS and the wall-to-OD ratio. A 4 in. Sch 40S length (6.02 mm wall on 114.3 mm OD) has wall over 5% of OD, so it takes +15.0% / -12.5%; the same size in Sch 10S (3.05 mm) takes +22.5% / -12.5%. NPS 2-1/2 and smaller take +20.0% / -12.5% at any wall.
When should I choose 316L instead of 304L seamless pipe?
Choose 316L once chlorides are present in the process stream, since its molybdenum adds the pitting and crevice resistance that chloride service calls for. For process, water and food lines without chlorides, 304L carries the lower indicative price per kg. Send the chloride content and temperature with your inquiry, and we will confirm the grade.
What is the largest SS 304L seamless pipe you can make?
Up to 1016 mm OD, with walls to 65 mm and lengths to 18 m. ASTM A312 lists stainless schedules up to NPS 30 (762 mm OD); larger diameters and heavier walls are made to the OD and wall on your drawing.
Which documents come with each lot of seamless S30403 stainless steel pipe?
Each heat ships with an EN 10204 3.1 (3.2 on request) certificate giving chemistry against the TP304L limits, tension and flattening results and the hydrostatic or electric test result. Every length is PMI checked, heat treatment charts and raw material certificates travel with the shipment, and independent third-party inspection can be arranged on request.
Request a Quote for Stainless Steel 304L Seamless Pipes
or email sales@thaida.co.th