The safe working load describes the maximum load to which a block may be subjected continuously during normal operation without causing damage or impairing its operational capability.
The breaking load, on the other hand, denotes the load limit at which the component fails – that is, breaks or ceases to function entirely.
As a general rule, we recommend a safety factor of at least four.
Example:
If a breaking load of 1,000 kg is specified in the catalogue, this results in a permissible working load of 250 kg (1,000 kg ÷ 4).
This fourfold safety margin is standard practice in the chain industry. In practical terms, this means that if a breaking load of, for example, 1,000 kg is determined, 50 per cent of this value – i.e. 500 kg – is set as the test load. No permanent deformation must occur under this test load. The safe working load is then half the test load, and is therefore 250 kg.
