When it comes to rigging hardware, such as shackles, hooks, or connectors, the following terms are commonly used:
Working Load Limit (WLL): The Working Load Limit refers to the maximum load that a piece of rigging hardware is designed to safely handle under normal working conditions. It is typically specified by the manufacturer and is based on factors such as the material, design, and safety factors of the hardware.
Proof Load (PL): The Proof Load is a percentage of the Breaking Load or Minimum Breaking Force (MBF) that rigging hardware must be able to withstand without permanent deformation. It is usually a fraction of the hardware's Breaking Load and is used as a test to ensure its strength and integrity.
Breaking Load (BL): The Breaking Load, also known as the Minimum Breaking Force (MBF), represents the maximum load at which the rigging hardware will break or fail. It is the load at which the hardware reaches its breaking point and should never be exceeded during use.
The Working Load Limit (WLL) is the most important value to consider when using rigging hardware. It determines the safe working load that the hardware can handle. It is crucial to ensure that the load being applied does not exceed the WLL of the specific piece of rigging hardware being used.
It is important to consult the manufacturer's specifications, guidelines, or industry standards for the specific rigging hardware you are using to determine the appropriate Working Load Limit (WLL), Proof Load (PL), and Breaking Load (BL) values. These values may vary depending on the type, size, and grade of the rigging hardware.
Always follow the manufacturer's recommendations and guidelines to ensure the safe and reliable use of rigging hardware. Exceeding the WLL or subjecting the hardware to loads beyond the Breaking Load can result in equipment failure, accidents, and potential harm to personnel.