What is P235GH steel plate?
P235GH is the base grade of EN 10028-2: P for pressure, 235 for the minimum yield in MPa, G for "other characteristics" and H for high temperature. It is an aluminium-killed, fine-grain carbon steel (C ≤ 0.16 %, Mn 0.60–1.20 %) delivered normalised or normalised-rolled, whose distinguishing feature is a certified 0.2 % proof strength at elevated temperature: 198 MPa at 100 °C, 165 at 200 °C, 136 at 300 °C and 116 at 400 °C for plate up to 16 mm. That table is what a boiler designer works from, and it is why P235GH — not the cheaper S235JR — must be used for any part of a pressure equipment shell under the PED or AD 2000. Its DIN predecessor was H I (DIN 17155); ASTM users compare it with A285 Grade C or A516 Grade 55. In practice it covers the low-pressure end of the market: hot-water boilers, steam boilers up to about 10 bar, calorifiers, air receivers and heat-exchanger shells at moderate temperature, where its excellent formability (flanging, dishing, tube-plate drilling) matters more than strength.
Chemical composition
| Element | C | Si | Mn | P | S | Al | Cr | Cu | Mo | Ni | N |
|---|---|---|---|---|---|---|---|---|---|---|---|
| max. % (ladle) | ≤ 0.16 | ≤ 0.35 | 0.60–1.20 | ≤ 0.025 | ≤ 0.015 | ≥ 0.020 | ≤ 0.30 | ≤ 0.30 | ≤ 0.08 | ≤ 0.30 | ≤ 0.012 |
Nb ≤ 0.010, Ti ≤ 0.03, V ≤ 0.02; Cr + Cu + Mo + Ni ≤ 0.70. CEV ≤ 0.35 typical.
Mechanical properties
| Thickness | Yield ReH min (MPa) | Tensile Rm (MPa) | Elongation A min | Impact KV |
|---|---|---|---|---|
| ≤ 16 mm | 235 | 360–480 | 24 % | 27 J at +20 °C (40 J long.) |
| > 16–40 mm | 225 | 360–480 | 24 % | 27 J at +20 °C |
| > 40–60 mm | 215 | 360–480 | 24 % | 27 J at +20 °C |
| Rp0.2 at 100 / 200 / 300 / 400 °C (≤ 16 mm) | 198 / 165 / 136 / 116 | — | — | — |
Equivalent grades
| System | Grade | Note |
|---|---|---|
| DIN 17155 | H I | direct predecessor |
| ASTM | A285 Gr. C / A516 Gr. 55 | A516-55 = 205 MPa yield |
| JIS G3103 | SB410 | |
| GB 713 | Q245R | |
| BS 1501 | 161-360A | historic |
| ISO 9328-2 | P235GH |
Thickness range and stock sizes
| Thickness | Widths × lengths | Availability |
|---|---|---|
| 3–6 mm | 1 500 / 2 000 × 6 000 | to order 1–3 weeks |
| 8–20 mm | 2 000 / 2 500 × 6 000–12 000 | to order 1–3 weeks |
| 25–60 mm | 2 000 / 2 500 × 6 000 | to order 2–4 weeks |
Weight per m² and per plate
| Thickness | kg/m² | 1 500 × 6 000 (kg) | 2 000 × 6 000 (kg) | 2 500 × 12 000 (kg) |
|---|---|---|---|---|
| 3 mm | 23.6 | 212 | 283 | 707 |
| 4 mm | 31.4 | 283 | 377 | 942 |
| 5 mm | 39.3 | 353 | 471 | 1 178 |
| 6 mm | 47.1 | 424 | 565 | 1 413 |
| 8 mm | 62.8 | 565 | 754 | 1 884 |
| 10 mm | 78.5 | 707 | 942 | 2 355 |
| 12 mm | 94.2 | 848 | 1 130 | 2 826 |
| 15 mm | 117.8 | 1 060 | 1 413 | 3 533 |
| 20 mm | 157.0 | 1 413 | 1 884 | 4 710 |
| 25 mm | 196.3 | 1 766 | 2 355 | 5 888 |
| 30 mm | 235.5 | 2 120 | 2 826 | 7 065 |
| 40 mm | 314.0 | 2 826 | 3 768 | 9 420 |
| 50 mm | 392.5 | 3 533 | 4 710 | 11 775 |
| 60 mm | 471.0 | 4 239 | 5 652 | 14 130 |
Nominal weights — mill tolerance to EN 10029 class A adds up to +4 % on thin plate; invoiced on theoretical weight unless agreed otherwise.
Welding, cutting and forming
P235GH welds like a good mild steel with a boiler-code discipline: qualified procedures (EN ISO 15614-1), low-hydrogen basic consumables (E38/E42 basic, G3Si1), no preheat below 30 mm, 50–75 °C above; post-weld heat treatment 550–600 °C is required by most codes above 30–35 mm wall. It flanges and dishes cold to a radius of 1.5 × t and hot-forms freely at 900–1 000 °C followed by normalising at 890–920 °C; tube plates drill and expand cleanly thanks to the fine-grain structure. Plasma-cut edges should be ground back 1–2 mm on pressure boundaries.
Where it is used
- Hot-water and low-pressure steam boiler shells and end plates
- Tube plates and smoke-tube plates
- Calorifiers and buffer tanks
- Air receivers and compressed-air vessels
- Heat-exchanger shells to 400 °C
- Autoclaves and small process vessels
P235GH vs P265GH
P265GH has 13 % more yield (265 vs 235 MPa) and a proportionally better elevated-temperature curve for a price difference of about 20 USD/t, which is why it is the standard boiler plate and P235GH the choice only where the design already fixes the grade or where maximum formability of thin plate is wanted. Both are available to order from the same mills; P265GH is also the grade we hold in limited stock.
Price
P235GH is priced with a boiler-grade premium of about 180 USD/t over the S235JR base — the elevated-temperature testing and normalised delivery cost more than the chemistry. The band below is the month's indicative FOB Istanbul range; 3.2 inspection and UT are added per ton.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
Packing for P235GH steel plate: plates banded on hardwood skids (max 5 t per pack), edges protected, heat numbers marked; One 40' HC carries 24–25 t of 6 m plate; short plate goes 20 t to a 20'. Over-length plate is loaded flat-rack, and heavy plate above 25 t per piece travels breakbulk from Derince. HS 7208.51 / 7208.52.
| Term | Detail |
|---|---|
| MOQ | 5 t of one thickness |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | To order 1–3 weeks (Turkish mill programme) |
| Packing | Skids up to 5 t, strapped, heat numbers stencilled |
| Container / truck | 40' HC ≈ 24–25 t of 6 m plate |
| Documents | Invoice, packing list, EN 10204 3.1 (3.2 on request), certificate of origin; SASO / SONCAP / PVoC on request |
| Payment | 30% advance, balance against B/L copy; L/C at sight for orders above 100 t |
Certificates and testing
Documentation for P235GH steel plate: EN 10204 3.1 mill certificate as standard (heat number, analysis, tensile, Charpy, condition); 3.2 with an independent inspector, EN 10160 UT reports and additional low-temperature Charpy tests are available on plates above 8 mm at order.
How to order
Send thickness × width × length, tonnage, the code (PED / AD 2000 / ASME comparison), certificate level, and whether impact testing at −20 °C or UT is required; for tube plates send the drilling drawing — we cut circles and rings to size.
Standards
- EN 10028-2:2017 — P235GH, 1.0345
- DIN 17155 — H I (withdrawn)
- PED 2014/68/EU material; AD 2000 W1
- EN 10029 class A/B; EN 10160 UT on request
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: P235GH · P265GH · P355GH
Frequently asked questions
What is the ASTM material equivalent to P235GH?
ASTM A285 Grade C (205 MPa yield) is the usual comparison; A516 Grade 55 is the closer normalised pressure-vessel grade. Neither certifies elevated-temperature yield the EN way, so the designer must accept the substitution.
What is the difference between P235GH and S235JR?
Same yield at room temperature, but P235GH is aluminium-killed, fine-grain, normalised and certified for yield strength up to 400 °C — mandatory for pressure equipment; S235JR is a structural steel with no elevated-temperature guarantee.
What temperature can P235GH be used at?
Continuous service up to about 400 °C for plate (the standard tabulates Rp0.2 to 400 °C); above that P265GH / P295GH or 16Mo3 are used.
Is P235GH the same as H I?
Yes — H I was the DIN 17155 name; P235GH (1.0345) is its EN 10028-2 successor.
Does P235GH need post-weld heat treatment?
By most codes only above 30–35 mm wall thickness (PWHT at 550–600 °C); thinner boiler shells are welded without.