ISO 17440:2014

Overview

ISO 17440:2014 - "Cranes - General design - Limit states and proof of competence of forged steel hooks" provides a harmonized framework for the design, verification and proof-testing of forged steel crane hooks and their machined shanks (thread/nut suspension). Intended to be used with other crane standards, it applies the limit state method (ISO 8686-1) to prevent hazards such as loss of strength (yield, ultimate, fatigue), excessive material temperatures and unintentional load disengagement. The standard covers hook bodies made from steel forgings and machined shanks up to specified material strength limits (ultimate ≤ 800 N/mm², yield ≤ 600 N/mm²) and excludes plate (rolled-plate) hooks.

Key topics and technical requirements

• Scope and definitions: hook body, shank, seat, suspension articulation and symbols for design calculations.
• Materials & workmanship: material property limits, heat treatment and manufacturing tolerances for forged hooks.
• Static strength: vertical and horizontal design forces, shank bending moments and proof of static strength.
• Fatigue strength: fatigue design forces, fatigue proof procedures and cumulative damage (Palmgren–Miner approach).
• Proof loading & testing: proof load requirements, proof of fitness, non-destructive testing (NDT) and sample testing procedures.
• Hook geometry & shank design: dimensional criteria, stress concentration considerations and guidance for shank/thread designs.
• Verification & conformity: manufacture verification, NDT, sampling rules and documentation.
• Information for use: marking, maintenance, inspection and safe-use guidance.
• Annexes: normative and informative annexes with sample hook sets, calculation examples, spectrum factors and suspension tilting resistance.

Practical applications

• Use ISO 17440:2014 for design verification of forged hook bodies and machined shanks in new cranes and lifting appliances.
• Apply it when performing proof load testing, NDT acceptance, or fatigue-life assessments for hooks.
• Reference it when developing product standards for specific crane types, specifying hook selection, inspection intervals and safe-use marking.
• Benefits include improved hook safety, predictable fatigue life, consistent proof testing and reduced risk of load disengagement.

Who should use this standard

• Crane designers and structural engineers
• Hook and forging manufacturers
• Third‑party testing, certification and inspection bodies
• OEMs of cranes and lifting equipment
• Maintenance and safety managers responsible for lifting operations

Related standards

Normative references include ISO 8686-1 (limit state design principles), ISO 12100 (machine safety/risk reduction), Charpy and tensile test standards (ISO 148, ISO 6892-1) and relevant forging/NDT standards. Use ISO 17440 together with these standards for comprehensive crane hook design and verification.

Keywords: ISO 17440:2014, forged steel hooks, crane hook design, limit states, fatigue strength, proof loading, hook shank, hook safety, crane standards.