What is S355ML? EN 10025-4 Structural Grade Supplier

 

 

What is S355ML? EN 10025-4 Structural Grade Supplier

Gangsteel – China's Leading Mill-Direct Supplier & Exporter of S355ML EN 10025-4 Structural Grade Plates

Gangsteel is your trusted partner for S355ML EN 10025-4 structural grade plates, with the largest ready stock in Asia – over 5,000 tons always available in thickness 6–200 mm, width 1500–4200 mm, length up to 18 meters. All plates are genuine TMCP (thermomechanical controlled process) produced by top mills like HBIS and Shougang, fully certified to EN 10025-4:2004 (2019 revision) with PED 2014/68/EU and CPR 305/2011 compliance.

We supply complete EN 10204-3.1/3.2 mill test certificates, third-party inspection (DNV-GL, ABS, Lloyd's Register, Bureau Veritas, CCS, RINA, KR, TÜV, SGS), Z25/Z35 through-thickness quality in stock, and 100 % ultrasonic testing EN 10160 S2/E2 standard.

Fast delivery worldwide in 3–7 days. Full processing services: plasma/oxy cutting, beveling, drilling, rolling, priming.

Browse our full en 10025 4 High Strength Structural Steel series for all grades.

 

What is S355ML? – Complete Grade Explanation

S355ML is a thermomechanically rolled (TMCP) weldable fine-grain structural steel defined in EN 10025-4:2004 (current version 2019).

The designation "S355ML" is decoded as follows:

• S= Structural steel (intended for load-bearing structures)
• 355= Minimum yield strength of 355 MPa (for thickness ≤ 16 mm, transverse direction)
• M= Thermomechanical rolling (TMCP delivery condition – controlled hot rolling + accelerated cooling, no separate normalizing)
• L= Low temperature impact toughness – minimum 27 J Charpy V-notch at –50 °C (longitudinal direction)

S355ML is specifically engineered for applications where high strength must be combined with reliable performance at low temperatures and excellent weldability.

The TMCP "M" is what makes S355ML special: it achieves a very fine-grained microstructure through the rolling process itself, resulting in:

• Lower residual stress than normalized grades
• Better flatness and dimensional stability
• Superior toughness in the heat-affected zone (HAZ) after welding
• Higher resistance to lamellar tearing (ideal for Z35 quality)

This is why S355ML has become the default choice for offshore wind turbine foundations, Arctic oil & gas structures, jack-up rigs, heavy mobile cranes, and cold-region bridges.

For a quick comparison with the most similar grade, see our detailed article S355M vs S355ML EN 10025-4 Steel Plate Comparison Supplier.

 

Chemical Composition – Ladle and Product Analysis Combined

Element	Ladle Max (%)	Product Deviation (%)	Typical Actual (%) – Gangsteel Stock	Role in S355ML Properties
C	0.14	+0.02	0.09–0.12	Low carbon for weldability & HAZ toughness
Si	0.50	+0.05	0.20–0.40	Deoxidizer
Mn	1.60	+0.10	1.20–1.50	Main strength contributor
P	0.025	+0.005	≤0.018	Low for toughness
S	0.020	+0.005	≤0.015	Low inclusions for impact values
Nb	0.05	+0.01	0.02–0.04	Primary grain refiner
V	0.10	+0.02	0.04–0.08	Precipitation strengthening
Al min	0.020	+0.030 (total)	0.025–0.045	Grain refiner & deoxidizer
Ti	0.05	+0.03	0.01–0.03	Nitride former
Cr	0.30	+0.05	0.10–0.25	Controlled hardenability
Ni	0.50	+0.05	0.20–0.40	Low-temp toughness improvement
Mo	0.10	+0.03	≤0.05	Minor HAZ improvement
Cu	0.55	+0.03	0.20–0.35	Deoxidizer
N	0.015	+0.003	≤0.012	Low for clean steel
CEV max	0.39	N/A	0.32–0.38	Excellent weldability (no preheat to 80 mm)

Full chemical breakdown: S355ML Chemical Composition EN 10025-4 Supplier

 

Mechanical Properties – Full Thickness Range up to 200 mm (Transverse)

Thickness (mm)	ReH min (MPa)	Rm (MPa)	A5 min (%)	KV min (J) at –50 °C longitudinal
≤ 16	355	470–630	22	27
>16 ≤ 40	345	470–630	22	27
>40 ≤ 63	335	470–630	22	27
>63 ≤ 80	325	470–630	22	27
>80 ≤ 100	315	470–630	22	27
>100 ≤ 120	305	450–610	22	27
>120 ≤ 150	295	450–610	22	27
>150 ≤ 200	285–295*	450–610	22	27

*Gangsteel guarantees 295 MPa up to 180 mm, 285 MPa to 200 mm.

Hardness: 140–180 HBW Density: 7.85 g/cm³ Full mechanical data sheet: S355ML Mechanical Properties EN 10025-4 Plate Supplier

 

Comparison Within EN 10025-4 Family

Grade	Yield (≤16 mm)	Impact Temp	CEV max	Preheat-free (mm)	Typical Use
S275M/ML	275 MPa	–20 / –50 °C	0.38	up to 100	Light structures
S355M	355 MPa	–20 °C	0.39	up to 80	Bridges, machinery
S355ML	355 MPa	–50 °C	0.39	up to 80	Offshore wind, Arctic
S420M/ML	420 MPa	–20 / –50 °C	0.43	up to 60	Heavy cranes
S460M/ML	460 MPa	–20 / –50 °C	0.46	up to 50	High-rise, heavy lifting

S355ML is the best-selling grade worldwide because it offers the perfect balance of strength, low-temperature toughness, weldability, and price.

Full comparison: S355M vs S355ML EN 10025-4 Steel Plate Comparison Supplier

 

Equivalent International Grades

Standard	Equivalent Grade	Key Match Notes	Typical Use Case
ASTM/ASME	A572 Gr.50 + Z35	Yield 345 MPa; –50 °C KV add	U.S. offshore
JIS G 3106	SM490A	Rm 490 MPa; –40 °C KV	Japanese marine
GB/T 1591	Q355E	Low-temp exact	China-EU projects
API 2W	Grade 50	Offshore weldable	Gulf/Baltic platforms
EN 10025-6	S355QL	QT alt; S355ML cheaper	Heavy lifts

Full equivalents: S355ML Equivalent Material EN 10025-4 Plate Supplier

 

Applications & Design Considerations

S355ML is used wherever high strength and low-temperature toughness are required:

• Offshore wind turbine foundations (monopiles, jackets)
• Arctic oil & gas structures
• Jack-up rigs and heavy mobile cranes
• Cold-region bridges and infrastructure
• Penstocks and pressure pipelines in alpine areas

Design advantages:

• 15–20 % weight reduction vs S355J2
• Excellent fatigue resistance
• No preheat up to 80 mm → faster fabrication
• Z35 quality prevents lamellar tearing in critical welds

 

Why Choose Gangsteel for S355ML Plates

• Largest S355ML stock in Asia (5,000+ tons ready)
• Factory-direct price – 60–120 USD/ton lower than traders
• Full processing capability (cutting, beveling, drilling, rolling, priming)
• Z35 quality always in stock
• Immediate delivery worldwide
• Exported to 90+ countries with perfect documentation
• One-stop service – stock → processing → shipping

 

FAQ – Quick Answers

Q1: What does S355ML mean?A: S = structural steel, 355 = minimum yield 355 MPa, M = thermomechanical rolled (TMCP), L = low temperature (–50 °C impact).

Q2: S355ML vs S355M difference?A: Only impact test temperature. S355ML = –50 °C (≥27 J), S355M = –20 °C (≥40 J). Strength, chemistry, weldability identical.

Q3: Preheating required?A: No preheat up to 80 mm thickness. >80 mm: 75–100 °C max.

Q4: Z35 availability?A: Yes – very large stock of S355ML + Z35 ready for immediate delivery.

Q5: Density and hardness?A: Density 7.85 g/cm³, hardness 140–180 HBW.

Q6: NDT standard?A: 100 % UT EN 10160 S2/E2 included. S3/E3, MT, PT on request.

Q7: Maximum thickness?A: Up to 200 mm with full properties and certification.

Contact Gangsteel Today

Need S355ML plates? Contact us now for best price and fastest delivery.

Email: admin@gangsteel.com WhatsApp/WeChat/Mobile: +86 135 9887 9167 Website: https://gangsteel.net/

Gangsteel – Real Factory. Real Stock. Real Fast Delivery.

 

Others relative propery of en 10025-4 S355ML