A chain sling is an essential piece of lifting equipment, typically manufactured from high-strength alloy steel. It is designed to connect a load to a lifting device, such as a crane or a hoist. A standard assembly consists of a top master link (which connects to the crane hook), one or more legs (the chain), and end fittings (hooks or other attachments) that connect directly to the load.

Where It Is Used & Applications

Chain slings are the "heavy hitters" of the rigging world and are preferred in environments where conditions are harsh. They are primarily used in:

• Construction: Lifting steel beams, pre-cast concrete structures, and heavy machinery.
• Manufacturing & Engineering: Moving heavy equipment on factory floors.
• Steel Mills & Foundries: Because they are made of steel, they can withstand high temperatures where synthetic slings (like polyester or nylon) would melt.
• Maritime/Shipping: Loading and unloading heavy cargo containers and ship components.
• Oil & Gas: Handling heavy drill pipes and offshore rig equipment.

Working Load Limit (WLL) Details

The Working Load Limit (WLL) is the maximum mass or force that a chain sling is authorized to support in general service when the load is applied vertically.

Important Note for Safety: The WLL of a chain sling is highly dependent on the angle of the legs. As the angle of the sling legs from the vertical increases, the tension in the legs increases, which significantly reduces the effective lifting capacity of the assembly.

Capacity Reduction Based on Angle

For a standard multi-leg sling, the WLL changes based on the angle at which the legs are positioned: 

• Rule of Thumb: Never lift at an angle greater than 60° from the vertical unless specifically engineered to do so, as the load on the chain increases exponentially.
• Grade Matters: Most industrial chains are Grade 80 or Grade 100. Grade 100 chains provide a higher WLL for the same diameter as Grade 80, allowing for lighter, more manageable slings.

Advantages of Chain Slings

Chain slings offer several distinct advantages over wire rope or synthetic webbing slings, making them a staple in high-duty industrial environments:

1. High Heat Resistance: They can be used in extreme temperatures (up to 400°C/750°F with minimal derating) without losing structural integrity.
2. Durability: They are resistant to sharp edges, abrasion, and punctures, which often destroy synthetic slings.
3. Flexibility: They are easy to wrap around irregular loads and can be adjusted in length using shortening hooks or clutches.
4. Inspectability: Wear, stretch, and damage to chain links are visually easier to identify compared to the internal wear of a wire rope.
5. Repairability: Unlike synthetic slings, which must be discarded when damaged, individual links or components of a chain sling can often be repaired or replaced by certified professionals, extending the service life of the equipment.