Steel S420M EN 10025-4 420MPa TMCP Plate Supplier

Steel S420M EN 10025-4 420MPa TMCP Plate Supplier

Gangsteel – China's Leading Mill-Direct Supplier & Exporter of Steel S420M EN 10025-4 420MPa TMCP Plates

Gangsteel is the professional supplier you can trust for steel S420M EN 10025-4 420MPa TMCP plates, with the largest permanent stock in Asia – over 4,000 tons always ready 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 with full European approvals and third-party inspection (DNV-GL, ABS, LR, BV, CCS, KR, TÜV, SGS).

Steel S420M is the mid-range high-strength grade in the en 10025 4 High Strength Structural Steel family, offering 420 MPa minimum yield strength and ≥40 J impact toughness at –20 °C. It is the direct TMCP alternative to normalized S420N (EN 10025-3) and the sister grade to the low-temperature bestseller S420ML (–50 °C).

We also stock the complete EN 10025-4 series, including the popular low-temperature grade en 10025 4 s420ml steel plate, the widely used en 10025 4 s355ml steel plate, higher-strength en 10025 4 s460m steel plate, top-end en 10025 4 s460ml steel plate, entry-level en 10025 4 s275ml steel plate and en 10025 4 s275m steel plate, as well as the standard-temperature en 10025 4 s355m steel plate.

What is Steel S420M EN 10025-4 420MPa TMCP Plate?

Steel S420M is a thermomechanically rolled (TMCP) weldable fine-grain structural steel specified in EN 10025-4:2004 (current version 2019).

The designation “S420M” means:

• S= structural steel
• 420= minimum yield strength 420 MPa (transverse, thickness ≤ 16 mm)
• M= thermomechanical rolling (TMCP delivery condition – controlled hot rolling + accelerated cooling, no separate normalizing)

The TMCP process gives steel S420M superior properties compared to normalized grades:

• Higher strength-to-weight ratio
• Lower residual stress
• Better flatness and dimensional stability
• Excellent weldability (CEV ≤ 0.48)
• Better fatigue performance and HAZ toughness

Steel S420M is the mid-range high-strength grade in the EN 10025-4 family, perfectly balancing cost, strength, and weldability when service temperature is above –20 °C.

Chemical Composition – Ladle Analysis (max % unless noted)

Typical Gangsteel actual values: C 0.09–0.13 %, CEV 0.40–0.46 → excellent weldability without preheating up to 80 mm thickness.

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

*Gangsteel guarantees higher values in thick plates by agreement.

Hardness: 150–200 HBW Density: 7.85 g/cm³

Available Specifications & Testing

• Thickness: 6–200 mm (20–120 mm most popular in stock)
• Width: 1500–4200 mm
• Length: up to 18 000 mm
• Z-quality: Z25 standard, Z35 large stock
• NDT: 100 % ultrasonic testing EN 10160 S2/E2 (S3/E3 optional)
• Surface: shot-blasted + primer or mill finish
• Certification: EN 10204-3.1/3.2, PED, CPR, all major class approvals

Applications of Steel S420M 420MPa TMCP Plates

Steel S420M is widely used when high strength is required:

• Mobile and crawler cranes
• Heavy lifting equipment
• Offshore crane pedestals
• Wind turbine towers (onshore)
• Bridge girders and trusses
• Mining equipment

When the temperature drops below –20 °C, the low-temperature version S420ML is required.

W

hy Choose Gangsteel for Steel S420M Plates

• Largest steel S420M stock in Asia (4,000+ 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

Summary

Steel S420M EN 10025-4 is a TMCP weldable fine-grain structural steel with 420 MPa yield strength and ≥40 J impact at –20 °C, offering an excellent balance of strength, weldability, and cost for applications above –20 °C. Gangsteel stocks over 4,000 tons of S420M with full certification and fast delivery, making it the reliable choice for cranes, bridges, and heavy equipment.

FAQ – Detailed Answers

Q1: What is the difference between S420M and S420ML?

A: The only difference is the impact test temperature. S420M is tested at –20 °C with minimum 40 J (longitudinal), while S420ML is tested at –50 °C with minimum 27 J. Yield strength, tensile strength, elongation, chemical composition, and weldability are exactly the same. Choose S420M when service temperature is above –20 °C; choose S420ML when below –20 °C.

Q2: Is preheating required when welding S420M?

A: No preheating is required up to 80 mm thickness thanks to the very low CEV (typically 0.40–0.46 actual). For thicknesses over 80 mm or highly restrained joints, a modest preheat of 75–100 °C is sufficient. This is a major advantage over many other structural steels.

Q3: Do you have Z35 quality in stock for S420M?

A: Yes – we keep very large stock of S420M + Z35 (reduction of area ≥35 % per EN 10164 Class 3), especially in 20–120 mm thickness, ready for immediate delivery. Z35 is essential for critical welded joints under tension perpendicular to the plate surface.

Q4: What is the density and hardness of S420M?

A: Density is 7.85 g/cm³ (7850 kg/m³), hardness is 150–200 HBW (typical 160–180 HBW in our stock). These values are consistent across the entire thickness range.

Q5: What NDT do you provide as standard?

A: 100 % ultrasonic testing to EN 10160 S2/E2 is included with every plate. We can upgrade to S3/E3, magnetic particle (MT), or penetrant testing (PT) on request at no extra charge for reasonable quantities.

Q6: What is the maximum thickness you can supply for S420M?

A: Up to 200 mm with full properties and certification. We guarantee minimum yield of 360 MPa up to 180 mm and 340 MPa to 200 mm – significantly better than the standard requirement.

Q7: How fast can you deliver to Europe or USA?

A: From ready stock: 7–12 days to Rotterdam, Antwerp, Houston, or Los Angeles. We have regular consolidation containers and can offer air freight for urgent small quantities (<10 tons) in 48–72 hours.

Contact Gangsteel Today

Need steel S420M 420MPa TMCP 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.

EN 10025-4 STEEL PLATE OTHER TECHNICAL DATA