Working Load: The working load limit is the maximum load that shall be applied in direct tension to an undamaged straight length of chain.
Proof Load: The proof load test is the load at which the chain has been pulled in a direct tension on a straight length of chain, using a standart chain testing machine during manufacturing process.
Breaking Load: The minimum breaking load is the minimum force at which the chain, during manufacture, has been found by testing to break when a constantly increasing force is applied in direct tension.
Instructions and cautions regarding the use of chain:
- Use only grade 80 (EN818–2) chain for overhead lifting applications.
- Do not overload. Know working load limits and load weight of chain; overloading can lead to rapid wear, stretching and sling failure that may cause serious injury or property damage.
- All attachments and accessories are designed for use with the appropriate size chain. Always make sure that the attachment is at least equal to the strength of the chain.
- Inspect the chain before lifting to remove all twist, knots and kinks.
- Avoid impact loading because loads that are jerked suddenly when picked up, can impose tension on the chain over the actuel load weight which may cause sling damage.
- Do not let chains come in contact with sharp corners of load without protective loading which may result bending, nicks and gouges.
- Do not add or weld any pieces to the chain other than factory’s standard.
- Do not drop or rest loads on chain that will lead to nicking or bending that may result in severe chain damage.
- Do not overheat the chain. Overheating may anneal the steel and may reduce the working load limits.
Proper chain care and extending the working life of chain;
- Store chain properly to avoid damage such as nicking, gouging, bending and corrosion which may require repair or replacement.
- Store chain away from heat.
- If storing for long periods of time, oil the chain before storage.
- Remove dirt and grit before storage as this can cause wear.
Inspecting the chain:
- Always inspect the chain before and after using it.
- Periodically measure the chain and keep records. Any chain inspected with deformation, elongation, nicks, gouges or breakes must be marked and immediately taken out of service.
- Do not use hardly rusted chains for lifting purposes.