What is the purpose of de-rating alloy chain slings?

De-rating alloy chain slings is primarily done to accommodate temperature variations. This process is essential because the mechanical properties of materials can change significantly under different temperature conditions. High temperatures can weaken the alloy, thereby decreasing its load-carrying capacity. Consequently, to maintain safety and ensure reliability during lifting operations, the working load limit (WLL) of the chain sling must be adjusted downward, or "de-rated," to reflect these changes.

Understanding the relationship between temperature and the performance of alloy materials is critical in rigging, as this knowledge helps prevent failures that could arise from using equipment that is no longer rated for the loads it is expected to handle. This is a critical aspect of ensuring safe lifting operations and maintaining compliance with industry standards.