Master links are essential, high-strength forged components used as the top attachment point in lifting slings (chain, wire rope, or synthetic) to connect to a crane hook. They are designed to withstand high stresses and properly distribute weight across multiple legs.
Capacity Matching: Ensure the Working Load Limit (WLL) of the master link meets or exceeds the maximum load being lifted.
Compatibility: Ensure the link is compatible with the hook size and the type/size of the sling (e.g., chain grade 80 or 100).
Angle Limitations: For multi-leg slings, the angle between the legs must not exceed the maximum allowed (typically 30° to 60°).
Free Movement: The master link must move freely on the crane hook and not be forced or wedged into place.
Back Hooking: If using a multi-leg sling but not all legs, “back hook” the unused legs onto the master link to prevent them from becoming snagged.
Connection Method: When attaching multiple slings to a single hook, use a master link instead of overcrowding the hook.
Never Overload: Never exceed the WLL marked on the tag or the link.
Inspection Before Use: Inspect for cracks, wear, deformations (stretching), and corrosion before every lift.
Avoid Shock Loads: Take up the load steadily to prevent sudden tension, which can exceed the WLL.
Remove from Service: Immediately remove a link if it shows signs of damage, such as a 10% or more reduction in diameter, bending, or unreadable markings.
Prohibited Actions: Do not heat treat, weld, or repair master links yourself.
No Point Loading: Do not lift on the point of a hook or on the edge of the master link.
Temperature Limits: Do not use in temperatures above 200°C or below -40°C without consulting the supplier.
Deformation: Check for elongation or “stretching” of the master link.
Cracks/Corrosion: Check for cracks, especially in welded areas, and deep pits from corrosion.
Wear: Look for wear at the bearing points (where it contacts the crane hook).
Identification: Ensure the identification tag is present, legible, and shows the WLL.
Store on a rack in a dry, clean, and non-corrosive environment, not on the ground.
Keep the master link clean and lightly lubricated if in a corrosive environment.
