Stainless Steel EFW Pipes to ASTM A358
Metinox Overseas manufactures stainless steel EFW pipes to ASTM A358, made by rolling stainless plate into a tube and welding the seam with filler metal. Each pipe is solution annealed after welding to restore corrosion resistance across the weld. We produce all five A358 classes. In simple terms, EFW pipe is what you order when a line is too big for standard welded pipe. Buyers in the GCC and other export markets use our pipes for desalination, refinery and gas plant headers, ordering by grade, size and class, which sets how the weld is made and radiographed. Explore the wider range in our stainless steel pipes.
Table of content
- Stainless Steel EFW Pipes Specification
- Stainless Steel EFW Pipe Grades and Where Each Is Used
- Electric Fusion Welded Pipe vs A312 Welded and Seamless Pipe
- SS EFW Pipe Dimensions and Weight Chart (ASME B36.19M)
- Chemical Composition of SS EFW Pipe Grades
- Mechanical Properties of Electric Fusion Welded Pipe
- EFW Pipe Equivalent Grades: UNS, EN and JIS
- Applications of Stainless Steel EFW Pipe
- What Sets the Price of an SS EFW Pipes
- Export Packing and Delivery
- SS EFW Pipe FAQs
Stainless Steel EFW Pipes Specification
| Parameter | Detail |
| Standard | ASTM A358 / ASME SA358 |
| Plate standard | ASTM A240 / ASME SA240 |
| Classes | Class 1, Class 2, Class 3, Class 4, Class 5 |
| Grades | ASTM A358 / ASME SA358: 304, 304L, 304H, 316, 316L, 316H, 317L, 321, 321H, 347, 347H, 310S (dual certified 304/304L and 316/316 |
| Stainless Steel EFW Pipes Outer Diameter Size | 6" NB to 110" NB (DN 150 to DN 2750); larger on request |
| Schedule (SCH) | SCH 5S, 10S, 40S, 80S to ASME B36.19M; SCH 40, 80, 160, XS, XXS to ASME B36.10M; custom wall thickness to design |
| Stainless Steel EFW Pipes Length | 1m to 12.5m, Single Random, Double Random, Customize Size. |
| Dimensional standards | ASME B36.19M, ASME B36.10M |
| Ends | Plain end, bevelled end to ASME B16.25 |
| Heat treatment | Solution annealed and quenched or rapidly cooled |
| Surface | Pickled and passivated |
| Certificate | EN 10204, type confirmed at quotation |
Stainless Steel EFW Pipe Grades and Where Each Is Used
| Garde | Best Use |
| SS 304 EFW pipe | General corrosion service, water and utility headers |
| SS 304L EFW pipe | Low carbon for welded construction without sensitisation |
| SS 316/316L EFW pipe | Molybdenum for better pitting resistance in chloride media |
| SS 317/317L EFW pipe | Higher molybdenum than 316L for more aggressive chemical service |
| SS 321/321H EFW pipe | Titanium stabilised for high temperature service |
| SS 347/347H EFW pipe | Niobium stabilised for high temperature service |
| SS 310S EFW pipe | Oxidation resistance at very high temperature |
Electric Fusion Welded Pipe vs A312 Welded and Seamless Pipe
| Point | Electric fusion welded pipe (A358) | Welded pipe (A312) | Seamless pipe (A312) |
| Starting material | Plate | Strip | Hollow billet |
| Filler metal | Yes | No | Not applicable |
| Typical size band | Large diameters and heavy walls | Small and medium diameters | Small and medium diameters, heavy walls |
| Weld inspection | Radiography set by class | Hydrostatic or NDE per standard | No longitudinal weld |
SS EFW Pipe Dimensions and Weight Chart (ASME B36.19M)
| NPS (in) | DN | OD mm (in) | Schedule | Wall mm (in) | Weight kg/m |
| 6 | 150 | 168.3 (6.625) | 5S | 2.77 (0.109) | 11.4 |
| 6 | 150 | 168.3 (6.625) | 10S | 3.40 (0.134) | 14.0 |
| 6 | 150 | 168.3 (6.625) | 40S | 7.11 (0.280) | 28.5 |
| 6 | 150 | 168.3 (6.625) | 80S | 10.97 (0.432) | 43.0 |
| 8 | 200 | 219.1 (8.625) | 5S | 2.77 (0.109) | 14.9 |
| 8 | 200 | 219.1 (8.625) | 10S | 3.76 (0.148) | 20.2 |
| 8 | 200 | 219.1 (8.625) | 40S | 8.18 (0.322) | 43.0 |
| 8 | 200 | 219.1 (8.625) | 80S | 12.70 (0.500) | 65.3 |
| 10 | 250 | 273.1 (10.75) | 5S | 3.40 (0.134) | 22.8 |
| 10 | 250 | 273.1 (10.75) | 10S | 4.19 (0.165) | 28.1 |
| 10 | 250 | 273.1 (10.75) | 40S | 9.27 (0.365) | 60.9 |
| 10 | 250 | 273.1 (10.75) | 80S | 12.70 (0.500) | 82.4 |
| 12 | 300 | 323.9 (12.75) | 5S | 3.96 (0.156) | 31.6 |
| 12 | 300 | 323.9 (12.75) | 10S | 4.57 (0.180) | 36.4 |
| 12 | 300 | 323.9 (12.75) | 40S | 9.53 (0.375) | 74.6 |
| 12 | 300 | 323.9 (12.75) | 80S | 12.70 (0.500) | 98.5 |
| 14 | 350 | 355.6 (14.0) | 5S | 3.96 (0.156) | 34.7 |
| 14 | 350 | 355.6 (14.0) | 10S | 4.78 (0.188) | 41.8 |
| 16 | 400 | 406.4 (16.0) | 5S | 4.19 (0.165) | 42.0 |
| 16 | 400 | 406.4 (16.0) | 10S | 4.78 (0.188) | 47.8 |
| 18 | 450 | 457.0 (18.0) | 5S | 4.19 (0.165) | 47.3 |
| 18 | 450 | 457.0 (18.0) | 10S | 4.78 (0.188) | 53.8 |
| 20 | 500 | 508.0 (20.0) | 5S | 4.78 (0.188) | 59.9 |
| 20 | 500 | 508.0 (20.0) | 10S | 5.54 (0.218) | 69.3 |
| 24 | 600 | 610.0 (24.0) | 5S | 5.54 (0.218) | 83.4 |
| 24 | 600 | 610.0 (24.0) | 10S | 6.35 (0.250) | 95.5 |
| 30 | 750 | 762.0 (30.0) | 5S | 6.35 (0.250) | 119.5 |
| 30 | 750 | 762.0 (30.0) | 10S | 7.92 (0.312) | 148.8 |
Weights are calculated as 0.02491 × (OD minus t) × t, in kg/m with OD and t in mm, and must be checked against the published tables.
Chemical Composition of SS EFW Pipe Grades
| Grade | C | Mn | Si | P | S | Cr | Ni | Mo | Other |
| 304 | 0.07 | 2.00 | 0.75 | 0.045 | 0.030 | 17.5 to 19.5 | 8.0 to 10.5 | n/a | N 0.10 |
| 304L | 0.030 | 2.00 | 0.75 | 0.045 | 0.030 | 17.5 to 19.5 | 8.0 to 12.0 | n/a | N 0.10 |
| 316 | 0.08 | 2.00 | 0.75 | 0.045 | 0.030 | 16.0 to 18.0 | 10.0 to 14.0 | 2.00 to 3.00 | N 0.10 |
| 316L | 0.030 | 2.00 | 0.75 | 0.045 | 0.030 | 16.0 to 18.0 | 10.0 to 14.0 | 2.00 to 3.00 | N 0.10 |
| 317L | 0.030 | 2.00 | 0.75 | 0.045 | 0.030 | 18.0 to 20.0 | 11.0 to 15.0 | 3.0 to 4.0 | N 0.10 |
| 321 | 0.08 | 2.00 | 0.75 | 0.045 | 0.030 | 17.0 to 19.0 | 9.0 to 12.0 | n/a | Ti 5×(C+N) min, 0.70 max |
| 347 | 0.08 | 2.00 | 0.75 | 0.045 | 0.030 | 17.0 to 19.0 | 9.0 to 13.0 | n/a | Nb 10×C min, 1.00 max |
| 310S | 0.08 | 2.00 | 1.50 | 0.045 | 0.030 | 24.0 to 26.0 | 19.0 to 22.0 | n/a | n/a |
Mechanical Properties of Electric Fusion Welded Pipe
| Grade | Tensile strength min, MPa (ksi) | Yield strength 0.2% min, MPa (ksi) | Elongation in 50 mm min, % | Hardness max |
| 304 | 515 (75) | 205 (30) | 35 | 201 HBW / 92 HRBW |
| 304L | 485 (70) | 170 (25) | 35 | 201 HBW / 92 HRBW |
| 316 | 515 (75) | 205 (30) | 35 | 217 HBW / 95 HRBW |
| 316L | 485 (70) | 170 (25) | 35 | 217 HBW / 95 HRBW |
| 317L | 515 (75) | 205 (30) | 35 | 217 HBW / 95 HRBW |
| 321 | 515 (75) | 205 (30) | 35 | 217 HBW / 95 HRBW |
| 347 | 515 (75) | 205 (30) | 35 | 201 HBW / 92 HRBW |
| 310S | 515 (75) | 205 (30) | 35 | 217 HBW / 95 HRBW |
EFW Pipe Equivalent Grades: UNS, EN and JIS
| ASTM grade | UNS | EN / W.Nr. | EN welded pipe standard | JIS |
| 304 | S30400 | 1.4301 | EN 10217 Part 7 | SUS304 |
| 304L | S30403 | 1.4307 | EN 10217 Part 7 | SUS304L |
| 316 | S31600 | 1.4401 | EN 10217 Part 7 | SUS316 |
| 316L | S31603 | 1.4404 | EN 10217 Part 7 | SUS316L |
| 317L | S31703 | 1.4438 | EN 10217 Part 7 | SUS317L |
| 321 | S32100 | 1.4541 | EN 10217 Part 7 | SUS321 |
| 347 | S34700 | 1.4550 | EN 10217 Part 7 | SUS347 |
| 310S | S31008 | 1.4845 | EN 10217 Part 7 | SUS310S |
Applications of Stainless Steel EFW Pipe
| Sector | Typical service |
| Desalination and water | Large bore brine and product water headers (see corrosion notes below for seawater) |
| Refining and petrochemicals | Process headers, flare and vent lines, high temperature transfer lines in 321 or 347 |
| Gas processing and LNG | Large bore process and utility lines, low temperature austenitic service |
| Fertilizer | Urea and nitric acid plant lines where the project specification fixes the grade |
| Power and flue gas treatment | Ducting and scrubber piping where diameter governs |
| Pulp, paper and chemicals | Stock and liquor lines in 316L and 317L |
What Sets the Price of an SS EFW Pipes
Every order is quoted to your specification. Price depends mainly on:
- A358 class: Classes 1 and 3 need full weld radiography, Classes 2 and 4 need none.
- Grade: nickel and molybdenum prices make 316L dearer than 304L.
- Size: larger diameters and heavier walls use more plate and may need extra seams.
- Quantity and length: including whether girth welds are allowed.
- Testing and paperwork: S1 to S6, your own specification, 3.1 or 3.2 certificate, third party inspection.
- Delivery terms: Incoterm and destination port.
For a quick quote, send: grade, standard, A358 class, OD, wall, length, quantity, end finish, certificate, inspection, destination port and required date.
Export Packing and Delivery
Packing for sea freight and storage:
- End caps or bevel protectors keep weld preparations undamaged.
- Timber saddles hold the pipe round and stop pipes rubbing in transit.
- No contact with carbon steel straps or chains, which can leave iron particles that rust.
- Wrapping keeps out salt air and sand at port and on site.
- A358 marking plus your shipping marks on every length, for easy checks on arrival.
SS EFW Pipe FAQs
We make EFW pipe from 6" NB up to 110" NB. Above 48" the wall thickness is set by your design code, and weights are calculated at quotation.
Yes. A358 pipe is a listed material in ASME B31.3. The longitudinal weld joint factor depends on the class, so fully radiographed Classes 1, 3 and 4 allow thinner walls than Class 2 for the same design pressure.
Use the class on your piping specification. Class 1 is double welded with full radiography, Class 3 single welded with full radiography, Class 5 double welded with spot radiography, and Classes 2 and 4 have no radiography. If the class is missing, ask the designer, because it changes weld efficiency and price.
A358 electric fusion welded pipe is made from plate and welded with filler metal, which suits large diameters and heavy walls. A312 welded pipe is formed from strip and welded without filler metal, and is normally used in smaller sizes. They are separate standards with separate testing rules.
Lengths of 5.8 m and 11.8 m fit 20 ft and 40 ft containers where the diameter allows. Very large diameters may need open top or flat rack equipment. The shipping method is confirmed at quotation.
Send the grade, standard and A358 class, OD, wall thickness, length, quantity, end finish, certification level, inspection requirements, destination port and required date. Attach your material specification if your project has one.
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