ISO 630-2:2021

Overview

ISO 630-2:2021 - "Structural steels - Part 2: Technical delivery conditions for structural steels for general purposes" defines delivery requirements for common hot‑rolled structural steels used in welded or bolted constructions. The standard covers plates (reversing mill), wide flats, hot‑rolled sections and bars in the as‑delivered condition, specifying grades, qualities, required tests and acceptance criteria. It is part of the ISO 630 series and is intended to harmonize chemical, mechanical and inspection rules for general structural steels.

Key topics and requirements

• Covered steel grades: Eight grades are standardized. Annex A covers S235, S275, S355 and S460; Annex B covers SG205, SG250, SG285 and SG345. Each annex is normative and applied separately.
• Qualities and impact testing: Four qualities (A, B, C, D):
  • Quality A - no impact testing
  • Quality B - Charpy V‑notch at +20 °C
  • Quality C - Charpy V‑notch at 0 °C
  • Quality D - Charpy V‑notch at −20 °C
    Default specimen orientation is longitudinal unless transverse orientation is agreed.
• Forms and thickness limits: Applies to hot‑rolled flat products and sections with specific nominal thickness ranges:
  • S460 long products: 3 mm ≤ t ≤ 150 mm
  • Other grades: long products 3 mm ≤ t ≤ 250 mm; flat products ≤ 400 mm
  • SG‑grades: no nominal thickness restriction for flat products, sections and long products.
• Chemical and mechanical controls: Requires heat and/or product analysis, tensile property verification, Charpy V‑notch impact testing where applicable, and a maximum carbon‑equivalent value for Annex A grades. Steels shall be killed (non‑rimming).
• Delivery condition and marking: Products may be supplied as‑rolled, normalized rolled, normalized, or thermomechanically processed. Delivery condition and inspection documentation must be specified.
• Sampling and test units: Typical test unit sizes specified (e.g., Annex A: 60 t per heat or part thereof; 80 t for heavy sections or large heats; Annex B: 50 t per heat). Inspection, sampling frequency and test methods reference ISO 630‑1.

Applications and users

ISO 630-2 is used by:

• Steel producers and mill operators for production and certification of hot‑rolled structural steels
• Structural engineers and fabricators specifying material for buildings, bridges, cranes and general welded/bolted structures
• Procurement and quality inspectors enforcing delivery conditions, tests and marking
• Third‑party testing and certification bodies

Practical applications include specifying appropriate grades and impact qualities for load‑bearing members, ensuring weldability and toughness, and setting inspection/test regimes for material acceptance.

Related standards

• ISO 630‑1 - General technical delivery conditions for hot‑rolled products (normative reference)
• ISO TC 17/SC 12 - continuous mill flat rolled products (sheet and strip)
• ISO TC 5/SC 1 - steel tubes (tubular products)

Keywords: ISO 630-2, structural steels, technical delivery conditions, hot‑rolled, S235 S275 S355 S460, SG205 SG250 SG285 SG345, Charpy V‑notch, tensile properties, chemical composition, welded structures.