S355M vs S355ML EN 10025-4 Steel Plate Comparison Supplier

S355M vs S355ML EN 10025-4 Steel Plate Comparison Supplier

Gangsteel – China's Largest Mill-Direct Stockist & Exporter of EN 10025-4 S355M and S355ML TMCP Structural Steel Plates

Gangsteel is the professional supplier for both en 10025 4 s355m steel plateand en 10025 4 s355ml steel plate. We keep more than 8,000 tons combined stock of S355M and S355ML year-round (thickness 6–200 mm), making us one of the biggest genuine stockists in Asia. All plates are TMCP produced with full traceability, EN 10204-3.1/3.2 certificates, and third-party inspection available (DNV, ABS, LR, BV, CCS, KR, TÜV, SGS).

S355M vs S355ML – The Only Real Difference is Impact Temperature

In the EN 10025-4 standard, S355M and S355ML are essentially the same steel – identical chemical composition, identical strength requirements, identical weldability, identical TMCP delivery condition.

The only difference is the Charpy impact test temperature:

• S355M → tested at –20 °C (minimum 40 J longitudinal)
• S355ML → tested at –50 °C (minimum 27 J longitudinal)

Everything else is 100 % the same.

This single difference makes S355ML the mandatory choice when the design temperature or service temperature is below –20 °C (offshore wind towers, Arctic structures, cold-region bridges, jack-up rigs, penstocks in alpine areas, etc.). S355M is perfectly sufficient for normal structural applications where the lowest service temperature stays above –20 °C.

In practice, S355ML has become the dominant grade because most modern projects (especially offshore wind and oil & gas) specify –40 °C or –50 °C design temperature to be on the safe side.

Chemical Composition – Ladle Analysis vs Product Analysis (EN 10025-4 + EN 10025-1 Table 4 tolerances)

Both grades have exactly the same chemical requirements.

Ladle Analysis – Maximum values unless range stated

Product Analysis– Permitted deviations per EN 10025-1 Table 4

*V +0.02 if agreed, +0.03 if V ≤ 0.12

Actual production values from Gangsteel mills are usually much tighter: C 0.08–0.12 %, CEV 0.34–0.37, P+S < 0.030 %.

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

Both grades have identical mechanical requirements.

** For t > 150 mm, minimum yield is usually 285–295 MPa depending on mill capability and agreement (most Chinese mills guarantee 295 MPa up to 180 mm, 285 MPa to 200 mm).

Typical Gangsteel actual values are 20–40 MPa above minimum, especially in 100–200 mm thickness.

Hardness: 140–180 HBW Density: 7.85 g/cm³ Through-thickness (Z-quality): Z25 standard, Z35 large stock

Practical Differences in Application

Real-world rule of thumb used by engineers:

• If your project specification says “minimum design temperature –20 °C” → S355M is acceptable and cheaper.
• If it says “–40 °C” or “–50 °C” or follows DNV-OS-B101, Norsok M-120, or EN 1993-1-10 → S355ML is required.

In the last 5 years, S355ML has taken 70–80 % market share in new offshore wind and oil & gas projects because clients prefer the extra safety margin of –50 °C toughness.

Weldability & Fabrication – Identical Performance

Both grades have the same very low CEV (typical 0.34–0.37 actual), so welding behaviour is identical:

• No preheating required up to 80 mm thickness (even 100 mm in many cases)
• Low-hydrogen consumables recommended (H10 max diffusible hydrogen)
• Maximum heat input 3.5–4.5 kJ/mm to preserve HAZ toughness
• PWHT not required unless specified

Gangsteel provides free welding recommendations and CEV/CET data for every heat number.

Why Customers Choose Gangsteel for S355M & S355ML

• Largest combined stock of S355M + S355ML in Asia (8,000+ tons)
• True factory price – 60–120 USD/ton lower than traders
• Full processing: plasma/oxy cutting, beveling, drilling, rolling, priming
• Z35 quality always in stock for both grades
• All major approvals (DNV, ABS, LR, BV, CCS, KR) ex-stock
• Exported to 90+ countries with perfect documentation
• One-stop service – stock → processing → shipping

FAQ – Quick Answers

Q1: Can I use S355M instead of S355ML to save money?A: Only if your design temperature is ≥ –20 °C and the specification allows it. Most offshore and cold-region projects now mandate S355ML.

Q2: Is the strength exactly the same?A: Yes – 100 % identical yield, tensile, and elongation requirements across all thicknesses.

Q3: Which one is more popular?A: S355ML is now 4–5 times more demanded than S355M globally, especially in offshore wind.

Q4: Do you have both in stock right now?A: Yes – large stock of both grades, 6–200 mm thickness, ready for immediate delivery.

Q5: What is the price difference today?A: S355ML is approximately 100–140 USD/ton higher than S355M (November 2025 market).

Contact Gangsteel for Best Price & Fast Delivery

Need S355M or S355ML plates? Contact us today for quotation within 2 hours.

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

Gangsteel – Real Factory, Real Stock, Real Price. We keep both S355M and S355ML ready – you choose the right one for your project.

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