Overview
ISO 3077:2001 specifies requirements for short-link, fine-tolerance hoist chain of Grade T - types T, DAT and DT - intended for use in manually operated or power-driven chain hoists. The standard applies to electrically welded, round steel short-link chain, heat-treated and tested per ISO 1834, in the nominal chain size range 3 mm to 22 mm. It covers dimensional tolerances, material and heat-treatment requirements, mechanical properties, verification tests, marking and documentation.
Key topics and technical requirements
- Scope & chain types
- Types DAT and DT: surface-hardened (case depth) for power-driven hoists only.
- Type T: may be used in lifting equipment other than hoists.
- Dimensions & tolerances
- Nominal sizes 3–22 mm, pitch based on 3·d (up to 3.2·d), weld diameter limited to max +8% over nominal.
- Detailed dimensioning and tolerance calculations are given in Annex A.
- Material & metallurgy
- Steel made by electric or oxygen-blown processes, fully killed, grain size ≤ 5 (ISO 643).
- Minimum alloying elements (e.g., Ni, Cr, Mo as appropriate per chain type) and limits for S + P to control brittleness.
- Heat treatment
- Chains shall be hardened, case-hardened, or both, and tempered from above the AC3 point before proof testing.
- Mechanical properties & loading
- Working Load Limits (WLL) specified for each nominal size and type (e.g., DAT 3 mm = 0.28 t up to DAT 22 mm = 15 t).
- Manufacturing Proof Force (MPF), breaking force, elongation and mean stress criteria are defined; calculation methods in Annex A.
- Verification & testing
- Sampling, MPF tests, breaking force, total ultimate elongation, bend deflection, Vickers hardness testing (ISO 6507-1) and fatigue resistance tests for types DAT/DT.
- Identification & documentation
- Requirements for grade marking, identification, inspection marks and manufacturer’s certificate; guidance on assembly, inspection and in-service use.
Applications - who uses ISO 3077:2001
- Chain manufacturers - to design, heat-treat and certify fine-tolerance hoist chain.
- Hoist and lifting-equipment designers - for component selection and WLL verification.
- Procurement and QA teams - to specify compliant chain for manual and power-driven hoists.
- Test laboratories and inspectors - for mechanical and fatigue testing, hardness checks and acceptance sampling.
- Maintenance and safety officers - to apply inspection intervals and replacement criteria stated in the standard.
Related standards
- ISO 1834 - Short link chain for lifting purposes: general conditions of acceptance
- ISO 643 - Steel: micrographic grain size
- ISO 6507-1 - Vickers hardness test
- ISO 4301-1, ISO 4965, EN 10002-2 - referenced for testing and classification
ISO 3077:2001 is essential when specifying fine-tolerance short-link hoist chain, ensuring dimensional control, material quality, heat treatment and verified mechanical performance for safe lifting operations.