# P355NH (1.0565) Open-Die Forgings

Source: https://www.steelforgepieces.com/Alloy-Steel/P355NH.html
Publisher: Jiangyin Jiangnan Metal Co., Ltd.
Last reviewed: 2026-09-14

P355NH, material number 1.0565, is a normalized weldable fine-grain steel for pressure
purposes with specified elevated-temperature properties. In the normalized (+N) condition
it gives a minimum upper yield strength of 355 MPa up to 16 mm and a tensile strength of
490-630 MPa up to 60 mm. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges
P355NH to EN 10222-4 as seamless rolled rings, sleeves, hollow bars, discs, tube sheets,
valve bodies, girth flanges, channel covers and long welding neck nozzles, supplied with
EN 10204 3.1 or 3.2 certification.

## At a glance

| Item | Value |
| --- | --- |
| Designation (EN 10027-1) | P355NH |
| Material number (EN 10027-2) | 1.0565 |
| Classification | Non-alloy elevated-temperature quality steel, weldable fine grain |
| Delivery condition | +N (normalized) |
| Density | 7.85 g/cm3 |
| Minimum yield ReH (t <= 16 mm) | 355 MPa |
| Tensile Rm (t <= 60 mm) | 490-630 MPa |
| Minimum elongation A (t <= 60 mm) | 22 % |
| Charpy longitudinal at -20 C | >= 40 J |
| Forging standard | EN 10222-4 |
| Plate standard | EN 10028-3 |
| Certification | EN 10204 3.1 or 3.2 |
| Manufacturer | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |

## Designation decoded (EN 10027-1)

- **P** - steel for pressure purposes
- **355** - minimum yield strength in MPa at the thinnest product thickness
- **N** - delivered normalized or normalized rolled
- **H** - elevated-temperature properties specified

## What P355NH is, and where it is used

P355NH is one of the weldable fine-grain steels used for pressure equipment. The grain
refinement from normalizing is what lifts proof strength to 355 MPa without costing notch
toughness at -20 C. It also keeps the grade weldable with ordinary consumables.

The H suffix means EN 10028-3 also specifies minimum proof strength at elevated
temperature, so the grade can be used for equipment running above ambient.

Common applications:

- Pressure vessels, separators, reactors and columns
- Steam drums, boiler parts and economiser components
- Shell-and-tube heat exchangers, including tube sheets and channel covers
- LPG and compressed-gas storage tanks
- Valve bodies, bonnets and closures for process piping
- Structural forgings that require a pressure-grade certificate

P355N, P355NL1 and P355NL2 sit in the same strength class and differ in impact test
temperature.

## Standards that cover P355NH

| Standard | Product form | Relevance to forgings |
| --- | --- | --- |
| EN 10222-4 | Steel forgings for pressure purposes | Primary standard for forged parts |
| EN 10028-3 | Flat products, normalized fine grain | Reference for properties |
| EN 10216-3 | Seamless tubes for pressure purposes | Mating components |
| EN 10217-3 | Welded tubes for pressure purposes | Mating components |
| EN 10253-2 | Butt-welding pipe fittings | Mating components |
| EN 10273 | Hot-rolled weldable bars for pressure purposes | Bar stock input |

For forgings, state EN 10222-4, delivery condition +N, the impact test temperature and the
certificate type (EN 10204 3.1 or 3.2).

## Chemical composition

Ladle analysis per EN 10028-3:2009, percentage by mass.

| Element | Limit |
| --- | --- |
| C | <= 0.18 |
| Si | <= 0.50 |
| Mn | 1.10-1.70 |
| Ni | <= 0.50 |
| P | <= 0.025 |
| S | <= 0.015 |
| Cr | <= 0.30 |
| Mo | <= 0.08 |
| V | <= 0.10 |
| N | <= 0.012 |
| Nb | <= 0.05 |
| Ti | <= 0.03 |
| Al | <= 0.02 |
| Cu | <= 0.30 |
| Nb + Ti + V | <= 0.12 |

These are specification limits, not typical values. Every heat ships with its own analysis
on the certificate. Forgings to EN 10222-4 use different limits: C <= 0.20, Si 0.10-0.50,
Mn 0.90-1.65, Ni <= 0.30, Al 0.020-0.060.

## Mechanical properties, condition +N

### Minimum upper yield strength ReH

| Nominal thickness (mm) | <= 16 | >16-40 | >40-60 | >60-100 | >100-150 | >150-250 |
| --- | --- | --- | --- | --- | --- | --- |
| ReH minimum (MPa) | 355 | 345 | 335 | 315 | 305 | 295 |

### Tensile strength Rm

| Nominal thickness (mm) | <= 60 | >60-100 | >100-150 | >150-250 |
| --- | --- | --- | --- | --- |
| Rm (MPa) | 490-630 | 470-610 | 460-600 | 450-590 |

### Elongation at fracture A

| Nominal thickness (mm) | <= 60 | >60-250 |
| --- | --- | --- |
| A minimum (%) | 22 | 21 |

### Charpy V-notch impact energy KV

| Test temperature | -20 C | 0 C | +20 C |
| --- | --- | --- | --- |
| Longitudinal minimum (J) | 40 | 47 | 55 |
| Transverse minimum (J) | 27 | 35 | 39 |

Test material comes from a prolongation or a sacrificial ring forged with the part, at the
sampling position given in EN 10222-4. If you need a different position, or a
through-thickness specimen, put it on the order before the forging is heat treated.

Source: EN 10028-3:2009 and EN 10222-4:1999. EN 10028-3 also specifies Rp0.2 at
temperatures up to 400 C. Actual results for a given heat appear on the mill test
certificate.

## Equivalent grades

Cross-references for guidance only. Any substitution needs written acceptance from the
design authority or notified body.

| Country or system | Grade | Note |
| --- | --- | --- |
| Europe, EN | P355NH / 1.0565 | The grade itself |
| Germany, DIN / WNr | WStE 355 | Former designation |
| United States, ASTM | A662 Gr. C | Nearest, not identical |
| France, AFNOR | A510AP | Nearest |
| United Kingdom, BS | 224 Gr. 490 | Nearest |
| Italy, UNI | FeE355-2 | Nearest |
| China, GB | Q345R | Nearest pressure-vessel grade |

## P355NH components forged by Jiangyin Jiangnan Metal

Forged to the customer drawing, or to a dimensional standard where there is no drawing, in
the +N condition.

- Forged rings and seamless rolled rings
- Sleeves, bushes and bushings
- Forged pipes, tubes, barrels, casings and shells
- Round bars, hollow bars and cylinders
- Hubs and housings
- Discs and disks
- Tube sheets and tube plates
- Valve bodies, blocks, bonnets, stems, closures and seat rings
- Girth flanges and cover flanges
- Channel covers for shell-and-tube exchangers
- Long welding neck (LWN) nozzle necks
- FVC-type self-reinforced nozzles
- Heat exchanger parts: shell flanges, spacers, baffles
- Forged and rough-machined shafts

## Manufacturing and certification

Process route:

1. Material input: ingot or continuous-cast billet from qualified steel mills, each heat traceable to its own analysis
2. Open-die forging: upsetting, drawing out and punching on hydraulic presses
3. Ring rolling: seamless rolled rings for shell flanges, girth flanges and cylindrical sections
4. Heat treatment: normalizing for the +N condition, or normalizing and tempering where specified; furnace charts go out with the certificate; simulated post-weld heat treatment on test coupons on request
5. Non-destructive testing: ultrasonic to EN 10228-3 or ASTM A388, magnetic particle to EN 10228-1, dye penetrant where specified; rings are rough turned before ultrasonic testing
6. Mechanical testing: tensile at room temperature, Charpy V-notch at the ordered test temperature, hardness, grain size
7. Machining: rough or finish machining on CNC lathes and boring mills

Certification:

- EN 10204 3.1 mill test certificate as standard
- EN 10204 3.2 countersigned by TUV, Lloyd's Register, Bureau Veritas, DNV or SGS on request
- Documentation to support fabrication under PED 2014/68/EU
- Third-party or customer witness inspection at any hold point

## What to include in an enquiry

1. Drawing or dimensioned sketch in PDF, DWG or STEP
2. Grade and standard: P355NH to EN 10222-4
3. Delivery condition: +N or +NT
4. Impact test temperature and orientation
5. Certificate type: EN 10204 3.1 or 3.2, and the inspection body if 3.2
6. NDT scope and acceptance class
7. Machining state: as forged, rough machined or finish machined
8. Quantity and required delivery date

## Questions

**What is P355NH steel?**
A normalized, weldable fine-grain steel for pressure purposes with specified
elevated-temperature properties, material number 1.0565. Covered by EN 10028-3 for plate,
EN 10222-4 for forgings, EN 10216-3 and EN 10217-3 for tubes, EN 10253-2 for fittings and
EN 10273 for bars.

**What does P355NH stand for?**
Under EN 10027-1: P for pressure purposes, 355 for minimum yield strength in MPa at the
thinnest thickness, N for normalized delivery, H for specified elevated-temperature
properties.

**What is the material number of P355NH?**
1.0565, under EN 10027-2.

**What is the yield strength of P355NH?**
Minimum ReH is 355 MPa up to 16 mm, 345 MPa from 16 to 40 mm, 335 MPa from 40 to 60 mm,
315 MPa from 60 to 100 mm, 305 MPa from 100 to 150 mm and 295 MPa from 150 to 250 mm.

**Which standard applies to P355NH forgings?**
EN 10222-4. EN 10028-3 is the plate standard.

**What is the difference between P355NH, P355NL1 and P355NL2?**
The guaranteed impact test temperature. P355NH is for elevated-temperature service,
P355NL1 is tested to -40 C and P355NL2 to -50 C.

**Is P355NH weldable?**
Yes, by SAW, SMAW, GTAW and GMAW. Calculate the carbon equivalent from the actual ladle
analysis on the certificate.

**What is the ASTM equivalent of P355NH?**
ASTM A662 Grade C is the nearest cross-reference, but not an automatic substitution.

**Who manufactures P355NH forgings in China?**
Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City,
Jiangsu Province, China. Email sales@steelforgepieces.com, telephone +86 189 2135 9659.

**Can P355NH forgings be supplied with EN 10204 3.2 certification?**
Yes, when stated on the purchase order.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
Open-die forging factory
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone and WhatsApp: +86 189 2135 9659
Email: sales@steelforgepieces.com
Web: https://www.steelforgepieces.com/

## Related grades

- Alloy steel: https://www.steelforgepieces.com/Alloy-Steel/
- Carbon steel: https://www.steelforgepieces.com/Carbon-Steel/
- Stainless steel: https://www.steelforgepieces.com/Stainless-Steel/
- Nickel alloy: https://www.steelforgepieces.com/Nickel-Alloy/
- Tool steel: https://www.steelforgepieces.com/Tool-Steel/

Figures on this page are the values specified by the standards and are given for guidance.
The governing values for any delivery are those printed on the mill test certificate.