Overview
ISO 6043:1985 - "Shipbuilding and marine structures - Eye and fork assemblies under tension load - Main dimensions" specifies the main dimensions, material grades and designation rules needed to ensure interchangeability of eye, fork and associated bolts or pins used under tension loads in shipbuilding and marine structures. First published in 1985, the standard covers dimensional tables (in millimetres), tolerance classes and material minimums for components used on cargo handling and lifting appliances. It is explicitly not applicable to components subject to compressive thrust or torsional loads.
Key topics and requirements
- Main dimensions and interchangeability
- Nominal sizes and corresponding main dimensions are tabulated for eyes, forks and connections (dimensions given in millimetres).
- A figure illustrates the permitted shape and key dimensional references for assembly parts.
- Designation and coding
- Simple designation rules for parts: code letters A (eye), B (fork), C (connection) plus nominal size (e.g., Eye ISO 6043 - A 10; Fork ISO 6043 - B 10; Connection ISO 6043 - C 10).
- Materials
- Eyes and forks: minimum steel grade Fe 360 per ISO 630.
- Bolts and pins: minimum steel grade Fe 430 per ISO 630.
- Option to use quenched & tempered (heat-treated) steels per ISO/R 683/1 when higher quality is required.
- Tolerances and fits
- Dimensional tolerances follow tolerance grade IT14 of ISO 286.
- Clearance hole-related dimensions are aligned with ISO 273 (fasteners - clearance holes).
- Scope limits
- Intended for components subject to tension only (examples: round-hole eyeplates, sheave block head fittings, block holders, trunnion pieces, turnbuckles).
- Securing methods for bolts/pins are left to national regulations.
Applications and who uses it
- Practical applications:
- Design and manufacture of shipboard lifting gear, rigging connections, cargo handling fittings and related marine hardware where predictable interchangeability and load-bearing performance under tension are required.
- Typical users:
- Shipbuilders, marine engineers, naval architects, rigging and hardware manufacturers, classification societies and ship repair yards.
- Benefits:
- Ensures dimensional compatibility between suppliers, supports safe load-bearing assemblies, and simplifies specification in technical drawings.
Related standards
- ISO 630 - Structural steels (Fe 360 / Fe 430)
- ISO/R 683/1 - Heat-treated steels (quenched & tempered)
- ISO 286 - ISO system of limits and fits (tolerance grade IT14)
- ISO 273 - Fasteners - Clearance holes for bolts and screws
- ISO 8147 - Shipbuilding vocabulary (definitions)
Keywords: ISO 6043, shipbuilding standard, marine structures, eye and fork assemblies, tension load, dimensions, materials, bolts, pins, interchangeability, lifting equipment.
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