What is P355NL1 Plate?
P355NL1 is a normalised, fine-grain weldable steel plate regulated by EN10028-3. The 'P' prefix signifies pressure application, '355' represents the minimum yield strength in MPa, 'N' indicates normalised heat treatment, and 'L1' specifies low-temperature impact testing to -40°C. This grade closes the performance disparity between normal pressure vessel steels and fully cryogenic materials, rendering it a cost-effective option for low-temperature applications without the need for nickel-alloy steels.
RPF Pipes & Fittings, Mumbai supplies P355NL1 plates. We have regular and non-standard thicknesses in stock. Fabrication-ready supplies can be cut, profiled, and sized. Complete mill test certifications ensure fast delivery across India. With over 15 years of supply expertise, the company serves oil and gas, petrochemical, power generation, and industrial engineering.
P355NL1 Plate Specifications
Review the following table for P355NL1 plate specifications, detailing standard dimensions, tolerances, and common industrial delivery conditions.
| Parameter | Details |
| Thickness Range | 6 mm to 150 mm (0.24" – 5.91") |
| Width | 1500 mm to 4020 mm (59" – 158") |
| Length | 3000 mm to 12000 mm (118" – 472") |
| Heat Treatment | Normalised (N) |
| Delivery Condition | Normalised or Normalised + Tempered |
| Impact Test Temperature | -40°C (NL1 requirement) |
| Testing Standards | EN10028-3, EN10160, EN10307 |
Chemical Composition
The table below lists chemical composition limits (in weight %) as per EN10028-3 for P355NL1 grade.
| Element | Symbol | Max / Range (%) |
| Carbon | C | 0.18 max |
| Silicon | Si | 0.50 max |
| Manganese | Mn | 1.00 – 1.70 |
| Phosphorus | P | 0.025 max |
| Sulfur | S | 0.010 max |
| Nitrogen | N | 0.012 max |
| Niobium | Nb | 0.05 max |
| Vanadium | V | 0.08 max |
Mechanical Properties
Properties are for plates up to 50 mm thick. Values for thicker plates may differ; consult the mill certification.
| Property | Value (Metric) | Value (Imperial) |
| Yield Strength (min) | 355 MPa | 51.5 ksi |
| Tensile Strength | 490 – 630 MPa | 71 – 91 ksi |
| Elongation (min) | 22% | 22% |
| Impact Test (Charpy V) | 27 J min at -40°C | 20 ft-lb min at -40°F |
P355NL1 Equivalent Grades
The following equivalents have been designed to serve as a general reference and are approximate. The suitability of the project should be verified by the specifications.
| Standard | Equivalent Grade |
| EN10028-3 | P355NL2 |
| ISO | FeE 355 |
Applications of P355NL1 Plates
Examine at the major industry uses of P355NL1 plates, which are suitable for working in low-temperature and high-pressure environments.
Pressure Vessels
For pressure containers, reactors, and separators, these plates are ideal gas processing industry components
Storage Tanks
Specially built for LNG storage tanks to provide the safe containment of a variety of cryogenic industrial fluids.
Boilers
These plates are made for cold-climate boilers and can hold a lot of pressure in utility and power systems.
Oil & Gas Industry
Critical for the oil & gas industry, specifically for offshore modules and pipelines in arctic environments.
Cryogenic and Low-Temperature Environments
Perfect for cryogenic and low-temperature environments, supporting refrigeration systems and robust cold storage structural frames.
Advantages / Key Features
We engineered P355NL1 as a fine-grained steel to improve structural safety and performance in tough spots. Explore the technical benefits this steel offers for your next project.
- High Impact Resistance: Guaranteed 27 J at -40°C ensures these plates remain durable and ductile in subzero temperatures.
- Excellent Weldability: Low carbon equivalent values effectively reduce cracking risks during the fabrication of complex pressure-bearing components.
- Strong Load-Bearing Capacity: A yield strength of 355 MPa ensures reliable support for high-pressure systems in a variety of industrial and energy sectors.
- Suitable for Harsh Environments: With the help of normalisation and grain refinement, uniform toughness can be achieved. This protects materials against brittle failure in harsh environments.
Why Choose Us?
RPF Pipes & Fittings, a Mumbai stockist, supplies P355NL1 plates. We maintain a full inventory of both standard and non-standard thicknesses for you. Custom cutting, plate profiling, and sizing are available for fabrication-ready supplies. Complete mill test certificates are provided to ensure prompt delivery to all destinations in India. With a supply capability that has been established for more than 15 years, the company provides services to the oil and gas, petrochemical, power generation, and industrial engineering sectors.
