S355NL vs S355N — what does the L add?

Only the impact test temperature and tighter impurity limits: NL is guaranteed at −50 °C with P ≤0.025% and S ≤0.020%, while N is tested at −20 °C. Chemistry and strength bands are otherwise the same, so NL is a drop-in upgrade for cold service.

Can S355J2 replace S355NL?

Not directly. S355J2 (EN 10025-2) is an as-rolled grade guaranteed only at −20 °C without the normalized fine-grain delivery condition. For −50 °C design temperatures the NL grade — or GB Q355E — is the correct specification.

Grades · Structural & HSLA Steel · S355NL

S355NL

Data verified

S355NL is the low-temperature grade of EN 10025-3 normalized fine-grain structural steels. It matches S355N in strength (yield ≥355 MPa, tensile 470–630 MPa) but guarantees Charpy toughness at −50 °C instead of −20 °C, with tighter P and S limits — the standard European choice for cold-climate and offshore structures.

DIN1.0546 (EN 10025-3)

AISIA572 Gr.50 (near)

GBQ355E (near)

CategoryStructural & HSLA Steel

Chemical composition

Element	Content (%)
C	≤0.18
Si	≤0.50
Mn	0.90–1.65
P	≤0.025
S	≤0.020
Nb	≤0.05
V	≤0.12
Al	≥0.02
Cr	≤0.30
Ni	≤0.50
Cu	≤0.55
CEV	≤0.43

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Yield strength	≥355 MPa (≤16 mm)
Tensile strength	470–630 MPa
Elongation	≥22%
Impact toughness	27 J at −50 °C
Density	7.85 g/cm³

Heat treatment

Supplied normalized or normalized-rolled (the "N" delivery condition) with fine-grain practice; no further heat treatment is normally required. Keep any PWHT below about 580 °C to protect low-temperature toughness.

Equivalent grades

Standard	Designation
din	1.0546 (EN 10025-3)
aisi	A572 Gr.50 (near)
gb	Q355E (near)

Compare side by side: S355NL vs S355J2 · S355NL vs Q355B · S355NL vs Q355D

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Offshore structures, wind towers, bridges, cranes, pressure-retaining structures in cold climates, low-temperature storage.

Processing: Very good weldability (CEV ≤0.43); fine-grain normalized structure gives a wide, forgiving welding window. Cut, drill and form with standard structural practice.

FAQ

S355NL vs S355N — what does the L add?: Only the impact test temperature and tighter impurity limits: NL is guaranteed at −50 °C with P ≤0.025% and S ≤0.020%, while N is tested at −20 °C. Chemistry and strength bands are otherwise the same, so NL is a drop-in upgrade for cold service.
Can S355J2 replace S355NL?: Not directly. S355J2 (EN 10025-2) is an as-rolled grade guaranteed only at −20 °C without the normalized fine-grain delivery condition. For −50 °C design temperatures the NL grade — or GB Q355E — is the correct specification.

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Source: EN 10025-3 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.