S420M Steel Plates

Hot-rolled fine-grain structural steel produced to the S420M grade, designed for heavy welded constructions requiring a high minimum yield and good low-temperature toughness. S420M delivers a guaranteed minimum yield strength of 420 MPa (for nominal thicknesses ≤ 16 mm) and is supplied in an "M" delivery condition that specifies minimum impact energy values at temperatures down to -20°C.

Key features

• Minimum specified yield strength: 420 MPa (≤ 16 mm nominal thickness).
• Delivery condition M: impact-tested to specified minima at temperatures not lower than -20°C.
• Available in flat product thicknesses up to 120 mm and long product thicknesses up to 150 mm.
• Weldable fine-grain structural steel suitable for heavy welded components.

Mechanical and performance notes

• Thermo-mechanical rolling gives improved strength and toughness; however, subsequent heating above ~580°C will reduce strength and should be avoided for thermo-mechanically rolled material.
• By arrangement, a notch impact energy of 27 J (longitudinal specimen) at –50°C can be warranted for applications requiring lower temperature performance.

Chemical / fabrication guidance

• Typical carbon equivalent (by arrangement):
  • Nominal size < 16 mm: 0.43%
  • Nominal size 16–40 mm: 0.45%
• Good weldability for common structural welding processes; specific welding procedure approvals should be used for critical fabrications.
• Cold forming (bending, folding, flanging) may be possible but suitability must be verified for the specific thickness and temper. Thermo-mechanically rolled grades are generally unsuitable for warm forming.

Typical applications

• Heavily loaded welded structures: bridges, flood gates, storage tanks, water-supply tanks and other structural components used at ambient or low temperatures.

Quality and ordering

• Supplied to recognized EN structural-steel specifications (see applicable EN 10025 series for S-grade requirements).
• Available for custom plate sizing, cut-to-length, and commercial processing — please provide thickness, plate size, required impact temperature, and any certification/inspection requirements when requesting a quote.

For quotations or technical clarifications, provide application details, required dimensions, and any testing/certification needs to obtain an accurate RFQ.