ISO 10721-1:1997

Overview

ISO 10721-1:1997 - Steel structures: Part 1 Materials and design establishes the principles and general rules for the selection of steel materials and the structural design of steel buildings. The standard covers fundamental design objectives, documentation, analysis methods and limit states. It is also stated as applicable to bridges, civil engineering and related structures, noting that those structures may require additional specific requirements.

Keywords: ISO 10721-1:1997, steel structures, materials and design, structural design, limit states

Key topics

• Scope, definitions and symbols - common terminology and notation needed for consistent design documentation.
• Design documentation - requirements for calculations, testing and written records supporting safe design decisions.
• Basic design principles - objectives, limit-state philosophy and recommended general design approaches.
• Basic variables - treatment of actions (loads), material properties (structural steels, connectors), geometric parameters and design resistance values.
• Structural analysis methods - elastic, elastic‑plastic and plastic analysis methods and guidance on structural behaviour.
• Ultimate limit states - member design, cross-sectional resistance, member stability, buckling (flexural, torsional, lateral‑torsional), and plate/web buckling.
• Connections - general requirements and detailed provisions for bolted and welded connections, including strength, slippage, hole deductions and weld types.
• Serviceability and fatigue - serviceability limit states, fatigue assessment procedures, stress spectra, fatigue strength curves, thickness and mean‑stress influences, and partial safety factors.
• Annexes - informative annexes expanding on variables, analysis, member resistance and fatigue procedures plus reference publications.

Keywords: buckling, bolted connections, welded connections, fatigue assessment, serviceability limit states

Practical applications

ISO 10721-1:1997 is intended for practitioners involved in the design, detailing and assessment of steel structures, including:

• Structural engineers and designers preparing building designs or adapting principles to bridges and civil engineering works
• Fabricators and detailers governing material selection, joint design and welding/bolting practices
• Inspectors and testing authorities documenting verification, testing and inspection regimes
• Code developers and standards committees seeking a harmonized limit‑state approach

The standard provides a framework to produce consistent, documented designs that address safety (ultimate limit states), usability (serviceability) and durability (fatigue).

Related standards and use

Use ISO 10721-1:1997 alongside national building codes and other ISO or EN standards covering steel grades, welding procedures and bridge-specific requirements to ensure full compliance for a given project or jurisdiction.

Keywords: structural design standard, ISO steel design, design documentation, limit states