Pressure vessel steel
P355NH / 1.0565 pressure vessel steel
P355NH is a normalised pressure vessel steel with Werkstoffnummer 1.0565 to EN 10028-3. NH marks normalised and suitable for elevated temperature. The yield strength is above P265GH – you change over when wall thickness or pressure makes P265GH too thick, not as a standard upgrade. INDUSTRISTÅL supplies plate and tube with 3.1. P355NL1 when low temperature is the requirement. 16Mo3 when the temperature calls for molybdenum.
Typical applications
- Pressure vessel plate with higher strength
- Vessels and boilers
- Tube and spool pipes
- PED equipment
Delivery conditions
- normalised / NH to EN 10028-3
Designations
- W.Nr.
- 1.0565
- EN standard
- P355NH
- DIN
- WStE355
- AISI/SAE
- A516 Gr.70
- SS (Sweden)
- 2106
- Group
- Pressure vessel steel
Chemical composition
Typical range according to EN 10028-3 (ladle analysis)
| Element | Range |
|---|---|
| C | max. 0.18 % |
| Si | max. 0.50 % |
| Mn | 0.90–1.70 % |
| P | max. 0.025 % |
| S | max. 0.015 % |
| Al | min. 0.020 % |
| N | max. 0.020 % |
Nb, Ti and V may be present as microalloying elements. The sum is limited in the standard.
Heat treatment
NH is the delivery condition in the standard. It is not +QT.
Machinability and weldability
Yes, as pressure vessel steel. Welding and NDT follow the plant's WPS – not an S355 swap.
Sawing and machining
Cutting to size and project supply. State thickness, DN/wall and the certificate the notified body expects.
Certificates and documentation
EN 10204 3.1 as standard. 3.2 and VdTÜV by arrangement, when the mill can issue it.
Dimension programme
| Form | Range | Note |
|---|---|---|
| Round bar | Bar to order | When the form is bar, not plate. |
| Plate | 8–100 mm thickness | Normalised. Switch when P265GH becomes too thick. |
| Seamless tube | Ø6–Ø2000 mm | Pressure tube. Wall to EN 10220. 3.1, 3.2 before we lock. |
| Fittings | Ø12–Ø2000 mm | ASME 1/2–60″ (Ø15–Ø1524 mm). Type A and B. Not a stock statement. |
| Flanges | Ø14–Ø2000 mm | ASME 1/2–60″ (Ø15–Ø1524 mm). PN 6–400. Not a stock statement. |
Parts of the range are held by European partners; other dimensions can be sourced. The range is not a current stock status in every diameter — stock is confirmed on enquiry.
Frequently asked questions
- What is P355NH?
- P355NH / 1.0565 is a normalised pressure vessel steel to EN 10028-3. Higher strength than P265GH.
- When should I use P355NH instead of P265GH?
- When the wall would otherwise become too thick, or the calculation calls for the 355 class. Not as an automatic upgrade.
- Do you supply P355NH tube?
- Yes. Plate and tube. State dimension, wall and certificate.
Read more
Send your enquiry
State grade, dimensions and quantity — or attach a drawing. We reply with a quote.