Overview
ISO 4347:2015 - Leaf chains, clevises and sheaves - specifies the dimensional, strength and test requirements for leaf chains and associated clevises and sheaves used for general lifting purposes. The fifth edition (2015) gives requirements for interchangeability, length measurement, preloading, minimum tensile strengths and minimum dynamic strengths, and includes rim profiles and chain-attachment geometry. Informative annexes describe methods for calculating chain dynamic strength and determining maximum test forces.
Key topics and technical requirements
- Scope and nomenclature
- Covers two series of leaf chains (designated LH/BL and LL) derived from ISO 606 / ASME references.
- Defines chain designation rules (pitch and lacing notation).
- Dimensions and interchangeability
- Tabulated minimum/maximum dimensions for pitch, plate thickness, pin diameter, plate widths and chain path depth (LH and LL series).
- Rim profiles for sheaves and chain-attachment ends of clevises to ensure fit and function.
- Strength and performance
- Minimum tensile strength and minimum dynamic strength requirements specified per chain size/series.
- Dynamic strength values are based on standardized test specimen lengths; methods for calculation are given in Annex A.
- Measuring forces, preloading and length validation
- Defines measuring forces for length checks, pre-loading procedures and length-validation methods to ensure proper assembly and service performance.
- Testing and marking
- Requirements for dynamic testing and guidance to determine maximum test force (Annex B).
- Marking and identification rules to aid traceability.
- Manufacturer and use notes
- Manufacturers remain responsible for actual product features. Chains from different manufacturers should not be combined in service.
Practical applications
- Specification is intended for general lifting applications such as hoists, winches, lifting gear, material handling systems and any equipment using leaf chains where predictable strength, interchangeability and fatigue performance are required.
- Useful for selecting chain, clevis and sheave combinations to meet load-bearing, fatigue and durability requirements in service.
Who should use this standard
- Mechanical designers and OEMs specifying lifting components
- Chain, clevis and sheave manufacturers and quality engineers
- Test laboratories and conformity assessors performing tensile and dynamic tests
- Procurement specialists and maintenance engineers ensuring correct parts, fit and safe operation
Related standards
- ISO 606 - short-pitch transmission chains and attachments (reference for chain derivation)
- ISO 15654 - fatigue test methods for roller and leaf chains
- ASME B29.8 - related leaf chain dimensions and practice
Keywords: ISO 4347:2015, leaf chains, clevises, sheaves, dimensions, tensile strength, dynamic strength, chain designation, LH series, LL series, interchangeability, preloading.
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