ISO 7597:2013

Overview

ISO 7597:2013 specifies safety and technical requirements for forged steel lifting hooks with latch, grade 8 (eye or clevis and pin) with working load limits (WLL) up to 63 t. The standard is intended mainly for hooks used in chain slings (ISO 4778 / ISO 7593), steel wire rope slings (ISO 7531) and textile slings, and covers design, dimensions, materials, testing, marking and instructions for use. It does not apply to hand‑forged hooks.

Key topics and requirements

• Scope and forms: Hooks may be of eye (E) or clevis (C) form (Table 1) and are primarily supplied as part of slings.
• Dimensions tied to WLL: Principal dimensions (seat diameter D, throat opening O, eye/clevis size F, etc.) are specified in Table 2 and derived from formulae in Annex A so dimensions scale with the working load limit (WLL).
• Materials & heat treatment: Requirements reference ISO 8539:2009 for materials, heat treatment, manufacturing and workmanship.
• Mechanical properties: Mechanical strength and acceptance criteria follow ISO 8539 procedures.
• Hook latches: Latches must be spring‑loaded (not gravity only), engage fully with the hook point, remain closed in any orientation and withstand:
  • 10 000 complete openings without fracture (corrosion‑protected spring),
  • Latch forces: equivalent to 300 kg or 10% of WLL, whichever is greater (but not exceeding 20 kN),
  • Guidance for latch opening torque is provided (Table 3).
• Verification & testing: Type tests, manufacturing tests and acceptance criteria follow ISO 8539. Latch type tests require three samples per size; failures render the latch non‑conforming.
• Marking & documentation: Marking, manufacturer’s declaration and instructions for use (assembly/disassembly and correct pin fit) are required.

Applications and users

ISO 7597:2013 is practical for:

• Manufacturers of forged steel lifting hooks and sling components
• Sling assemblers and rigging shops producing chain, wire rope and textile slings
• Crane, lifting and rigging engineers specifying components by WLL and grade 8
• Inspection and testing laboratories performing type and production tests
• Safety officers, purchasers and asset managers who need compliant, traceable lifting hardware

Using ISO 7597 helps ensure consistent component dimensions, reliable latch performance and traceable testing, reducing lift risk and improving interchangeability across slings.

Related standards

• ISO 8539:2009 - Forged steel lifting components for use with Grade 8 chain (normative reference)
• ISO 4778 - Chain slings of welded construction
• ISO 7593 - Chain slings assembled by methods other than welding
• ISO 7531 - Wire rope slings for general purposes

Keywords: ISO 7597:2013, forged steel lifting hooks, grade 8, working load limit, WLL, hook latch, chain slings, wire rope slings, textile slings, ISO 8539.