A single-leg sling is constructed from a single "leg" (one strand or assembly) rather than branching into multiple legs. Often designated by specific end-fitting letter codes (such as an SOG sling with an oblong master link on top and a grab hook on the bottom), these slings are the fundamental building blocks of industrial rigging.
While a single-leg sling has a load factor of 1.0 in a perfectly vertical lift, changing the hitch type drastically alters its real-world safe capacity.
Factor of 1.0. The full Working Load Limit (WLL) is available. The sling hangs straight down at a 90° angle between the hook and the load.
Factor of 0.8. Because of the acute angle created when the sling body bites down on itself, the safe lifting capacity typically drops to 80% (or lower depending on the severity of the angle of choke).
Factor of 2.0. While a single-leg sling routed completely under a load in a basket hitch can technically double the capacity, it must only be used if the load is perfectly balanced to prevent slipping.
Note: As the sling angle shifts away from absolute vertical, the tension on the sling increases, and the effective WLL decreases.
A single-leg sling may be used to securely connect a lifting appliance directly to a load equipped with a dedicated, single lifting point, such as a certified eyebolt on a heavy electric motor.
It may also be utilized in a choke hitch configuration. This is achieved either by "back hooking" the sling onto itself or by reeving one end of the sling through its own eye. This grips the load tightly but reduces the overall capacity by at least 20%.
Two identical single-leg slings may be used in combination to form, in effect, a two-leg sling. Care is strictly necessary to ensure that the hook of the lifting appliance is not overcrowded. It is recommended that the upper ends of the sling legs be cleanly connected via a master link or bow shackle.
Critical Rule: Where this is done, the legs must be symmetrically disposed, and the angle of any leg should not exceed 45° to the vertical. The combined SWL when the legs are at an angle between 0° and 45° to the vertical (0° to 90° included angle) is 1.4 times the SWL of a single leg.
1. Hardware Deformation: Inspect the Master Link and the Hook. If the hook's throat opening has increased by more than 10% from its original manufactured size, the sling is permanently compromised and must be destroyed.
2. Sling Body Wear: The criteria vary strictly by material type:
3. The ID Tag: If the manufacturer's WLL tag is missing, illegible, or detached, the sling is legally "dead" and cannot be used for any overhead lifting under OSHA or ISO regulations.
