Overview
ISO 7592:1983 provides guidelines for the safe use, inspection, in‑service testing and maintenance of calibrated round steel link lifting chains that operate over chain wheels. The standard targets chains used in manual and power‑driven hoists and emphasizes correct chain/pocket‑wheel interaction, lubrication, handling and record keeping. It also notes that lifting chains may be subject to national and local regulations.
Key topics & technical requirements
- Chain/wheel interaction
- Distinguishes idler wheels (change direction only) from driving/pocket wheels (change direction and tension) and explains pocket geometry, guides, strippers and the risks of wrong pitch.
- Proper use
- Chains must be aligned with the wheel, kept under light tension to preserve gauge length, and prevented from becoming twisted or overloaded.
- Avoid chain coatings (e.g., hot galvanizing) unless approved by the chain manufacturer because coatings can change pitch or mechanical properties.
- Lubrication
- Maintain lubrication at interlink contact points using high‑cling, high‑pressure lubricants; avoid lubricants that contaminate handled materials when inappropriate.
- Service classification & inspection intervals
- Defines service classes: light, moderate, heavy, very heavy.
- Frequent (visual) inspections: typical intervals - monthly (light) up to daily (very heavy).
- Periodic (detailed) inspections: yearly (light) to six‑weekly (very heavy) with records.
- Rejection criteria
- Reject chains showing cracks, severe nicks/gouges, visible distortion, severe corrosion, irremovable deposits, or excessive elongation.
- Where manufacturer guidance is absent, replace chain if gauge length over 5–11 links exceeds unused chain by 2% (power driven) or 3% (manually operated).
- In‑service testing
- Routine tests no more often than annually; test force not to exceed 1.5 × working load limit or 1.5 × appliance rated capacity. Apply load gradually and perform link‑by‑link inspections after testing.
- Replacement & repair
- Use only calibrated chains that match the original dimensional and material specification; repair is not recommended.
- Record keeping
- Maintain continuous records of chain identification, inspection dates/results, tests and maintenance.
Applications & users
- Practical for manufacturers of lifting appliances, hoist designers, maintenance engineers, safety officers, plant managers and regulatory inspectors. Applicable to operations using chain blocks, overhead hoists and other pocket‑wheel chain drives.
Related standards
Open preview (PDF)Calibrated round steel link lifting chains — Guidelines to proper use and maintenance