P265GH steel (1.0425): properties, composition, equivalents
P265GH (1.0425, ex HII) is the EN 10028-2 pressure-vessel steel: 265 MPa yield, 410–530 MPa tensile, 27 J at −20 °C, Rp0.2 guaranteed to 400 °C. Composition, elevated-temperature table, A516-60/SA-516 equivalents.
What is P265GH?
P265GH is the standard carbon-steel plate for boilers, pressure vessels and heat exchangers in Europe: P for pressure, 265 for the minimum yield in MPa, G for 'other characteristics' and H for guaranteed high-temperature properties. Werkstoff number 1.0425; the pre-1992 name HII (DIN 17155) is still in wide use, especially in Turkey, Germany and the Gulf.
What separates it from a structural steel of the same strength is the guarantee package: yield strength tabulated from 50 to 400 °C, Charpy 27 J at −20 °C transverse, sulphur held to 0.010 %, full killing with aluminium, normalized microstructure, and mandatory testing per plate under the Pressure Equipment Directive (EN 10028-2 with EN 10204 3.1/3.2 certification). Tensile is 410–530 MPa, elongation 23 %.
The usual US counterpart is ASTM/ASME A516 Grade 60 (yield 220 MPa) — a 'near' match because yield is lower and elevated-temperature values are handled differently in ASME. JIS SB410, GB Q245R and IS 2002 Grade 2 are closer. For service above ~450 °C the next step is 16Mo3.
P265GH chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.2 | |
| Si | ≤ 0.4 | |
| Mn | 0.8 – 1.4 | |
| P | ≤ 0.025 | |
| S | ≤ 0.01 | very low sulphur for through-thickness ductility in vessels |
| Al | ≥ 0.02 | total Al; fully killed |
| N | ≤ 0.012 | |
| Cr | ≤ 0.3 | |
| Cu | ≤ 0.3 | |
| Mo | ≤ 0.08 | |
| Nb | ≤ 0.02 | |
| Ni | ≤ 0.3 | |
| Ti | ≤ 0.03 | |
| V | ≤ 0.02 |
EN 10028-2:2017 Table 1; Cr + Cu + Mo + Ni ≤ 0.70 %. CEV max 0.40 % (≤ 60 mm), 0.42 % (60–100 mm). Normalized delivery (+N) is mandatory for plate > 16 mm.
P265GH mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| ≤ 16 mm, +N | 265 (38.4) | 410–530 (59.5–76.9) | 23 | ≈ 120–160 HB (typ.) |
| > 16 ≤ 40 mm | 255 (37.0) | 410–530 (59.5–76.9) | 23 | — |
| > 40 ≤ 60 mm | 245 (35.5) | 410–530 (59.5–76.9) | 23 | — |
| > 60 ≤ 100 mm | 215 (31.2) | 400–520 (58.0–75.4) | 22 | — |
| > 100 ≤ 150 mm | 200 (29.0) | 390–510 (56.6–74.0) | 21 | — |
| Rp0.2 at 100 °C (≤ 60 mm) | 226 (32.8) | — | — | — |
| Rp0.2 at 200 °C | 205 (29.7) | — | — | — |
| Rp0.2 at 300 °C | 173 (25.1) | — | — | — |
| Rp0.2 at 400 °C | 145 (21.0) | — | — | — |
EN 10028-2 Tables 2–4; transverse test pieces for plate. Elevated-temperature yield values decrease slightly for thickness > 60 mm. Creep data (EN 10028-2 Annex) allow use to about 480 °C for time-dependent design.
Impact toughness
P265GH requires a minimum Charpy V-notch energy of 27 J at -20 °C (transverse; ≥ 40 J longitudinal at −20 °C; ≥ 31 J transverse at 0 °C and ≥ 34 J at +20 °C). The 'GH' suffix (G = other characteristics, H = high temperature) marks elevated-temperature yield guarantees plus low-temperature impact.
P265GH equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| Q245R | GB/T (China) | Identical | GB/T 713 Q245R: yield 245 MPa, Rm 400–520 MPa, 31 J at 0 °C; C ≤ 0.20, Mn 0.50–1.10 — the Chinese boiler and pressure-vessel plate matching P265GH/HII. |
| IS 2002 Gr. 2 | IS (India) | Identical | IS 2002 Grade 2 pressure-vessel plate: yield 240 MPa, Rm 410–530 MPa. |
| SB410 | JIS (Japan) | Identical | JIS G3103 SB410 boiler plate: yield ≥ 225 MPa, Rm 410–550 MPa, C ≤ 0.24; SPV235 (G3115) is the pressure-vessel equivalent. |
| A516 Gr. 60 | ASTM / ASME | Near | ASTM A516 Grade 60 (SA-516-60): yield 220 MPa (32 ksi), Rm 415–550 MPa; C ≤ 0.21–0.27 by thickness, no elevated-temperature yield table (ASME Section II-D gives allowables). Closest US boiler-plate grade. |
| A516 Gr. 65 | ASTM / ASME | Near | Yield 240 MPa, Rm 450–585 MPa — slightly stronger than P265GH. |
| A516 Grade 70 | ASTM / ASME | Near | Yield 265 MPa, Rm 410–530 MPa — the EN grade most often substituted for A516-60/65; slightly weaker than Grade 70. |
| P235GH | EN (European) | Near | 1.0345 (ex HI): yield 235 MPa, Rm 360–480 MPa — the lower class; common for tubes. |
| P295GH | EN (European) | Near | 1.0481 (ex 17Mn4): yield 295 MPa, Rm 460–580 MPa. |
| 16K / 20K | GOST (Russia/CIS) | Near | GOST 5520 16K (yield 245, Rm 400–490) and 20K (yield 245, Rm 410–520): Russian boiler plates. |
| A285 Gr. C | ASTM / ASME | Functional | Yield 205 MPa, Rm 380–515 MPa; lower-quality pressure plate for low-pressure vessels. |
| 16Mo3 | EN (European) | Functional | Mo-alloyed step for service above 400–450 °C. |
| S275JR | EN (European) | Functional | Structural steel of similar strength without elevated-temperature or pressure-equipment certification (no PED compliance). |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for P265GH →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| HII | DIN 17155 (withdrawn 1992) | The classic German boiler-plate grade; still the ordering name in much of Europe and the Middle East. |
| Fe410-1KW / Fe410-2KW | EN 10028-2:1992 / ISO 9328 | |
| P265GH (1.0425) | EN 10028-2:1992 | Name and number unchanged since 1992. |
| 161 Gr 400 / 164 Gr 400 | BS 1501 (withdrawn) | Grade 400 (≈ 410 MPa tensile) is the match. |
| A42CP / A42AP | NF A 36-205 |
Product forms and tolerance standards
Product forms: plate (EN 10028-2, dominant), strip and sheet (EN 10028-2), seamless tube for pressure (EN 10216-2), welded tube (EN 10217-2), forgings (EN 10222-2 as P280GH), fittings (EN 10253-2).
Dimensional tolerances: plate: EN 10029 (class A/B thickness, flatness N); strip: EN 10051; tube: EN 10216-2 / EN ISO 1127.
Key property values
P265GH yield strength
265 MPa (38.4 ksi) ≤ 16 mm, 255 MPa to 40 mm, 245 MPa to 60 mm, 215 MPa to 100 mm, 200 MPa to 150 mm. Elevated temperature (≤ 60 mm): 226 MPa at 100 °C, 205 at 200 °C, 173 at 300 °C, 145 MPa at 400 °C.
P265GH tensile strength
410–530 MPa (59–77 ksi) up to 60 mm; 400–520 MPa to 100 mm; 390–510 MPa to 150 mm.
P265GH hardness
Not specified in EN 10028-2; normalized plate is typically 120–160 HB. NACE MR0175 sour service: ≤ 22 HRC is comfortably met.
Impact toughness
Transverse 27 J at −20 °C, 31 J at 0 °C, 34 J at +20 °C; longitudinal 40 / 47 / 55 J.
Maximum service temperature
Design tables to 400 °C (time-independent); creep rupture data allow time-dependent design to about 480 °C. Above that use 16Mo3 or 13CrMo4-5.
Physical properties
Density 7.85 g/cm³, E = 212 GPa at 20 °C (200 GPa at 300 °C), expansion 12.0 × 10⁻⁶/K (20–100 °C) to 13.5 (20–400 °C), conductivity ≈ 50 W/m·K.
Weldability
Very good weldability (CEV ≤ 0.40 %): all arc processes, E42/G42 or E46 consumables with low hydrogen for pressure work. Preheat normally unnecessary below 30 mm; EN 1011-2 governs thicker joints. PWHT (stress relief 550–600 °C) is required by EN 13445 / AD 2000 above certain thicknesses (typically > 35 mm) or for specific services (H₂S, caustic). Welding procedures must be qualified per EN ISO 15614-1 for PED equipment.
Machining, forming and heat treatment
Machines like a mild structural steel (index ≈ 70 %). Cold forming: dished ends and shells are cold-formed within EN 13445 strain limits (typically ≤ 5 % without post-forming normalizing); hot forming 900–1050 °C followed by re-normalizing 890–950 °C. Flame cutting is routine; grind cut edges for vessels in cyclic service.
Typical applications
- Steam boilers, boiler drums and headers (low-pressure and firetube boilers)
- Pressure vessels, air receivers, LPG storage vessels (with impact requirements)
- Heat-exchanger shells, tubesheets (thin), channels
- Hot-water storage tanks and district-heating equipment
- Seamless pressure tubes (EN 10216-2 P265GH) for boilers and superheaters up to 400 °C
- Autoclaves, sterilizers and process vessels in food and chemical plants
P265GH compared with related grades
Frequently asked questions
Is P265GH the same as HII?
Yes. HII (DIN 17155) became P265GH (EN 10028-2) in 1992 with harmonized limits; material certified to EN 10028-2 P265GH fulfils an old HII requirement.
What is the ASTM equivalent of P265GH?
ASTM/ASME A516 Grade 60 is the usual substitute (yield 220 MPa, Rm 415–550 MPa); Grade 65 is closer in strength. Neither has the EN elevated-temperature yield table, and for PED-marked equipment a European Approval for Materials or particular material appraisal is needed.
What is the maximum temperature for P265GH?
400 °C for design using the tabulated yield values, up to about 480 °C where creep-rupture data are applied. For higher temperatures switch to 16Mo3 (≈ 530 °C) or 13CrMo4-5 (≈ 570 °C).
P265GH or S275JR — what is the difference?
Similar room-temperature strength, but P265GH is a pressure-equipment steel: certified per plate under EN 10028-2, with guaranteed yield at elevated temperature, low sulphur, −20 °C impact and normalized structure. S275JR is a structural steel and cannot be used for PED-scope pressure parts without specific appraisal.
Does P265GH need PWHT?
Not for weldability, but the vessel code decides: EN 13445 and AD 2000 require stress-relief above threshold thicknesses (around 35 mm for carbon steel) and for services such as wet H₂S or caustic.
Related grades
Verified against EN 10028-2:2017; EN 10028-2:2017 Tables 1–4; EN 10028-1:2017 (general); ASME SA-516 (comparison). Last checked: September 2026.