ERW Pipe
Electric-resistance-welded (ERW / HFI) pipe — high-frequency welded from coil, no filler metal, economical for standard sizes — in carbon-steel grades to ASTM, API and IS.
Technical specification
| Parameter | Specification |
|---|---|
| Product | Electric-resistance-welded (ERW / HFI) circular carbon-steel pipe |
| Manufacturing route | High-frequency induction / resistance welding from coil; no filler metal; seam bead scarfed |
| Dimensional standard | ASME B36.10M · IS 1239 Part 1 (nominal-bore classes) · API 5L |
| Size range | 1/2" – 24" NPS — Sagiant’s confirmed ERW scope, not a universal ERW maximum |
| Wall / class | Schedules per B36.10M; IS 1239 Light / Medium / Heavy; API 5L walls — size-specific, not every combination |
| Material specifications | ASTM A53 Type E, A135, A795; API 5L (HFW, PSL1 / PSL2); ASTM A500 / A252 (structural / piling); IS 1239 Part 1 |
| Sour service | API 5L PSL2 alone does not establish sour service; NACE MR0175 / ISO 15156 qualification where required |
| Documentation | EN 10204 3.1 / 3.2, PMI, TPI, coil / heat traceability |
How it is made
ERW pipe is formed continuously from steel coil: the strip is slit to width, roll-formed into a cylinder, and the edges are joined by high-frequency induction (HFI) heating and forge pressure — no filler metal is added. HFI is the modern high-frequency route within the wider ERW family; the older term “ERW” also covered low-frequency contact welding, which is not what is offered here. The external (and, where specified, internal) weld bead is scarfed, the seam is normalised or seam-annealed where the specification requires, and the pipe is sized, straightened, tested and finished — bare, or hot-dip galvanised for IS 1239 / A795 where applicable. The seam is examined by ultrasonic or eddy-current methods per the product standard; radiography does not apply to a resistance seam. Schedule or class defines a nominal wall, not a pressure rating; the actual wall follows the B36.10M / IS 1239 table and the design code.
| Step | Detail |
|---|---|
| Coil preparation | Slitting to strip width, edge trimming |
| Forming | Roll-forming the strip into a cylinder |
| Welding | High-frequency induction heating + forge pressure (no filler) |
| Bead removal | External (and internal where specified) seam scarfing |
| Seam treatment | Normalising / seam anneal per specification |
| Sizing & test | Sizing, straightening, hydrotest, seam NDE (UT / eddy-current) |
| Finishing | Cut to length, bevel / thread, bare or galvanised, marking |
For a product with no weld seam see seamless pipe; for large-diameter fusion-welded pipe see LSAW / SSAW or the welded pipe overview.
Grades & materials
ERW / HFI is a carbon-steel product. The specifications below are the verified ERW scope; availability by grade, size and finish is confirmed on quotation. Seamless, EFW, stainless, duplex and nickel pipe are covered on their own pages, not here.
| Application | Grades | Standard | Notes |
|---|---|---|---|
| Water & general utility | A53 Type E Gr.A, Gr.B | ASTM A53 | Water, gas, low-pressure process |
| Line pipe | API 5L Gr.B, X42, X46, X52, X56, X60, X65, X70 (PSL1 / PSL2, HFW) | API 5L | Oil & gas transmission |
| Mechanical / general | A135 Gr.A, Gr.B | ASTM A135 | General & mechanical service |
| Fire protection | A795 Gr.A, Gr.B (black / galvanised) | ASTM A795 | Sprinkler pipe — UL / FM is a separate product listing |
| Structural (circular) | A500 Gr.B, Gr.C (round HSS) | ASTM A500 | Structural only — no pressure rating |
| Piling | A252 Gr.2, Gr.3 | ASTM A252 | Cylindrical pipe piles — not a pressure specification |
| Nominal-bore (IS) | IS 1239 Part 1 Light / Medium / Heavy | IS 1239 | Black or galvanised; classes are not schedules or grades |
IS 1239 Part 1 — nominal bore, OD & class wall
| NB (mm) | OD (mm) | Light | Medium | Heavy | |||
|---|---|---|---|---|---|---|---|
| t | kg/m | t | kg/m | t | kg/m | ||
| 15 | 21.3 | 2.00 | 0.95 | 2.60 | 1.20 | 3.20 | 1.43 |
| 20 | 26.9 | 2.30 | 1.40 | 2.60 | 1.56 | 3.20 | 1.87 |
| 25 | 33.7 | 2.60 | 1.99 | 3.20 | 2.41 | 4.00 | 2.93 |
| 32 | 42.4 | 2.60 | 2.55 | 3.20 | 3.09 | 4.00 | 3.79 |
| 40 | 48.3 | 2.90 | 3.25 | 3.20 | 3.56 | 4.00 | 4.37 |
| 50 | 60.3 | 2.90 | 4.11 | 3.60 | 5.03 | 4.50 | 6.19 |
| 65 | 76.1 | 3.20 | 5.75 | 3.60 | 6.44 | 4.50 | 7.95 |
| 80 | 88.9 | 3.20 | 6.76 | 4.00 | 8.38 | 4.80 | 9.96 |
| 100 | 114.3 | 3.60 | 9.83 | 4.50 | 12.2 | 5.40 | 14.5 |
| 125 | 139.7 | — | — | 4.85 | 16.1 | 5.40 | 17.9 |
| 150 | 165.1 | 4.50 | 17.8 | 4.85 | 19.2 | 5.40 | 21.3 |
Chemical composition (representative)
| Grade | Spec | C | Mn | P max | S max | Other |
|---|---|---|---|---|---|---|
| A53 Type E Gr.A | A53 | 0.25 max | 0.95 max | 0.05 | 0.045 | Cu 0.40, Ni 0.40, Cr 0.40, Mo 0.15, V 0.08 |
| A53 Type E Gr.B | A53 | 0.30 max | 1.20 max | 0.05 | 0.045 | Cu 0.40, Ni 0.40, Cr 0.40, Mo 0.15, V 0.08 |
| A135 Gr.A | A135 | 0.25 max | 0.95 max | 0.05 | 0.06 | — |
| A135 Gr.B | A135 | 0.30 max | 1.20 max | 0.05 | 0.06 | — |
| API 5L Gr.B | API 5L PSL1 | 0.28 max | 1.20 max | 0.030 | 0.030 | welded; PSL2 limits tighter |
| API 5L X52 | API 5L PSL2 | 0.24 max | 1.40 max | 0.025 | 0.015 | Nb+V+Ti ≤0.15, CE limits |
| API 5L X60 | API 5L PSL2 | 0.24 max | 1.40 max | 0.025 | 0.015 | Nb+V+Ti ≤0.15, CE limits |
| API 5L X70 | API 5L PSL2 | 0.24 max | 1.60 max | 0.025 | 0.015 | Nb+V+Ti ≤0.15, CE limits |
| A795 Gr.A | A795 | 0.25 max | 0.95 max | 0.05 | 0.045 | Fire protection |
| A795 Gr.B | A795 | 0.30 max | 1.20 max | 0.05 | 0.045 | Fire protection |
| A500 Gr.B | A500 | 0.26 max | 1.35 max | 0.035 | 0.035 | Structural; Cu 0.20 min if specified |
| A500 Gr.C | A500 | 0.30 max | 1.35 max | 0.035 | 0.035 | Structural |
| A252 Gr.2 / 3 | A252 | — | — | 0.05 | — | Piling — mechanically governed |
| IS 1239 Part 1 | IS 1239 | 0.20 max | 1.30 max | 0.05 | 0.05 | Black / galvanised; per IS edition |
Standards & specifications
Dimensional & product
- ASME B36.10M carbon dimensions · IS 1239 Part 1 nominal-bore classes
- ASTM A53 Type E · A135 · A795 ERW carbon pipe
- API 5L PSL1 / PSL2 welded (HFW) line pipe
- ASTM A500 (circular structural) · A252 (piling) — separate from pressure pipe
Marking, testing & service
- Seam NDE by ultrasonic / eddy-current — radiography does not apply to a resistance seam; methods are not interchangeable
- Hydrostatic test; flattening / bend for seam ductility
- IS 1239 to BIS / ISI-licensed manufacture; A795 UL / FM is a product listing, not implied by A795 alone
- API 5L PSL2 alone does not establish sour service (NACE MR0175 / ISO 15156 where required)
- Schedule or class is a nominal wall, not a pressure rating
Mechanical properties (representative grades)
Representative grades — full MTC values on request. Values are specification minima at room temperature; a flattening / bend test verifies seam ductility. Structural (A500) and piling (A252) values are for structural / geotechnical design, not pressure service.
| Grade | Spec / basis | Tensile min (MPa) | Yield min (MPa) | Elong min (%) |
|---|---|---|---|---|
| A53 Type E Gr.A | ERW carbon | 330 | 205 | — |
| A53 Type E Gr.B | ERW carbon | 415 | 240 | — |
| A135 Gr.A | ERW carbon | 330 | 205 | — |
| A135 Gr.B | ERW carbon | 415 | 240 | — |
| API 5L Gr.B | Line (HFW) | 415 | 245 | — |
| API 5L X42 | Line (HFW) | 414 | 290 | — |
| API 5L X52 | Line (HFW) | 460 | 360 | — |
| API 5L X60 | Line (HFW) | 520 | 415 | — |
| API 5L X65 | Line (HFW) | 535 | 450 | — |
| API 5L X70 | Line (HFW) | 570 | 485 | — |
| A795 Gr.A | Fire protection | 330 | 205 | — |
| A795 Gr.B | Fire protection | 415 | 240 | — |
| A500 Gr.B (round) | Structural | 400 | 290 | 23 |
| A500 Gr.C (round) | Structural | 425 | 315 | 21 |
| A252 Gr.2 | Piling | 415 | 240 | — |
| A252 Gr.3 | Piling | 455 | 310 | — |
| IS 1239 Part 1 | NB pipe | 320 | — | 20 |
Testing, inspection & documentation
| Test / document | Detail |
|---|---|
| Chemical / PMI | Product-analysis chemistry; PMI where alloying is specified. PMI does not replace full chemistry. |
| Tensile | Base-metal tensile, yield and elongation (ASTM A370) |
| Flattening / bend | Flattening (and bend where required) to verify seam ductility |
| Seam NDE | Ultrasonic or eddy-current of the weld seam — radiography does not apply to a resistance seam; UT / ET / hydrotest are not automatically interchangeable |
| Hydrostatic | Hydrotest to the product standard, or NDE in lieu where permitted |
| Galvanising | Coating mass / uniformity for galvanised pipe (IS 4736 / A53 / A795 as applicable) |
| Certification | EN 10204 3.1 as standard; 3.2 validated by an independent authorised party |
| Marking | Maker, standard, size, class / grade, heat; API monogram or BIS mark only where held by the manufacturer |
Applications & industries served
Dimensions, schedules & theoretical weight
Outside diameter, wall thickness and plain-end theoretical mass. ERW is supplied in carbon steel; mass is kg/m = π × t × (D − t) × ρ × 10⁻⁶ with ρ = 7850 kg/m³; lb/ft ≈ kg/m × 0.672; nominal ID = D − 2t. Figures are for bare plain-end pipe and exclude galvanising, coating and couplings. ERW availability is typically Sch 10–80 to ~24"; heavier walls and larger diameters are supplied seamless or SAW.
ASME B36.10M schedules (carbon steel)
| NPS | OD (mm) | STD | XS | Sch 160 | XXS | ||||
|---|---|---|---|---|---|---|---|---|---|
| t | kg/m | t | kg/m | t | kg/m | t | kg/m | ||
| 1/2 | 21.3 | 2.77 | 1.27 | 3.73 | 1.62 | 4.78 | 1.95 | 7.47 | 2.55 |
| 3/4 | 26.7 | 2.87 | 1.69 | 3.91 | 2.20 | 5.56 | 2.90 | 7.82 | 3.64 |
| 1 | 33.4 | 3.38 | 2.50 | 4.55 | 3.24 | 6.35 | 4.24 | 9.09 | 5.45 |
| 1-1/4 | 42.2 | 3.56 | 3.39 | 4.85 | 4.47 | 6.35 | 5.61 | 9.70 | 7.77 |
| 1-1/2 | 48.3 | 3.68 | 4.05 | 5.08 | 5.41 | 7.14 | 7.25 | 10.15 | 9.55 |
| 2 | 60.3 | 3.91 | 5.44 | 5.54 | 7.48 | 8.74 | 11.1 | 11.07 | 13.4 |
| 2-1/2 | 73.0 | 5.16 | 8.63 | 7.01 | 11.4 | 9.53 | 14.9 | 14.02 | 20.4 |
| 3 | 88.9 | 5.49 | 11.3 | 7.62 | 15.3 | 11.13 | 21.3 | 15.24 | 27.7 |
| 4 | 114.3 | 6.02 | 16.1 | 8.56 | 22.3 | 13.49 | 33.5 | 17.12 | 41.0 |
| 6 | 168.3 | 7.11 | 28.3 | 10.97 | 42.6 | 18.26 | 67.6 | 21.95 | 79.2 |
| 8 | 219.1 | 8.18 | 42.5 | 12.70 | 64.6 | 23.01 | 111.3 | 22.23 | 107.9 |
| 10 | 273.0 | 9.27 | 60.3 | 12.70 | 81.5 | 28.58 | 172.3 | 25.40 | 155.1 |
| 12 | 323.8 | 9.53 | 73.9 | 12.70 | 97.4 | 33.32 | 238.7 | 25.40 | 186.9 |
| 14 | 355.6 | 9.53 | 81.3 | 12.70 | 107.4 | 35.71 | 281.7 | — | — |
| 16 | 406.4 | 9.53 | 93.3 | 12.70 | 123.3 | 40.49 | 365.4 | — | — |
| 18 | 457.0 | 9.53 | 105.2 | 12.70 | 139.2 | 45.24 | 459.4 | — | — |
| 20 | 508.0 | 9.53 | 117.2 | 12.70 | 155.1 | 50.01 | 564.8 | — | — |
| 24 | 610.0 | 9.53 | 141.1 | 12.70 | 187.1 | 59.54 | 808.3 | — | — |
IS 1239 Part 1 nominal-bore class dimensions and weights are in the Grades & materials section above. NPS / NB / DN are size designations, not measured OD; STD / XS are not universally equal to Sch 40 / 80; IS classes are not schedules.
Provide with your enquiry
- Standard / edition, grade / type / PSL or IS class.
- NPS / NB / OD and wall, schedule or class.
- Length, ends and finish (bare / galvanised).
And the commercial detail
- Required tests and certification (3.1 / 3.2, PMI).
- UL / FM or BIS scope where applicable.
- Quantity, coating, delivery location and any BOQ.
Frequently asked questions
What does ERW pipe mean, and is it the same as HFW?
ERW (electric-resistance welded) pipe is formed from coil and joined at the seam by electric-resistance heating and forge pressure, without filler metal. HFW (high-frequency welding / HFI) is the modern high-frequency route within the ERW family — the process we offer — but “ERW” historically covers other process distinctions too, so we describe the actual high-frequency route rather than treating every ERW as identical.
What is the maximum size of ERW pipe you supply?
Our confirmed ERW circular-pipe scope is up to NPS 24. That is Sagiant’s supplied limit, not a universal maximum for ERW manufacture, and it does not imply that all larger pipe must use another process. Actual OD / wall combinations are confirmed per grade.
Is Sch 40 the same as STD, and does the schedule set the pressure?
STD and XS are weight-class designations, not the end of a numbered schedule series. STD equals Sch 40 only up to NPS 10 and XS equals Sch 80 only up to NPS 8; above those they diverge (for example NPS 12 STD 9.53 mm vs Sch 40 10.31 mm). A schedule defines a nominal wall, not an allowable pressure — pressure design is a code calculation using stress at temperature, minimum wall after tolerance and corrosion allowance.
What size range does galvanised IS 1239 pipe cover?
IS 1239 Part 1 covers nominal bore 6–150 mm in Light, Medium and Heavy classes — not a blanket 12″ range — supplied black or galvanised, from BIS/ISI-licensed manufacturers. Those IS classes are separate from A53 schedule pipe and are not alloy grades or direct schedule equivalents, so the class, size, finish and ends are stated per order.
Is A795 pipe automatically UL Listed or FM Approved?
No. ASTM A795 is a material specification; a UL Listing or FM Approval is a specific manufacturer product listing tied to a size, wall, finish, connection method and permitted service. A795 compliance does not by itself grant a UL / FM listing, so we confirm the actual listed product and its scope for fire-protection use.
Is ERW line pipe suitable for high-pressure or sour service?
It can be, but not automatically. PSL2 plus seam NDE does not by itself establish sour, hydrogen or CO&sub2; suitability — that requires project-specific design, material, process and qualification to the applicable standard and edition (and API 5L’s 47th edition, 2026, revised HFW, toughness and sour-service requirements). The ordered edition and service conditions are confirmed for each project.
What information is needed for a quotation?
Provide the standard and edition, type / grade / PSL and delivery condition, NPS or actual OD, wall or class, length, quantity, finish / coating, end preparation, service and design conditions, required tests and documents, and the delivery date. Availability by grade and size is confirmed with the quotation.
Request a quote
Send your requirement to Sagiant Piping Industries and our team responds with grade, material selection, availability and pricing for erw pipe. Attach a BOQ, line list or drawing for a faster, more accurate quotation.
- Fast RFQ response with grade & material-selection support
- EN 10204 3.1 / 3.2 certification, PMI & third-party inspection
- BOQ & line-list project supply — India & export
Mechanical & chemical values shown are ASTM/ASME specification figures; certified heat-specific values appear on the MTC. Availability is confirmed with the quotation.
