In a four-leg sling, the angle between any two diagonally opposite legs should not _______.

• A. exceed 180 degrees
• B. exceed 90 degrees
• C. be less than 30 degrees
• D. be greater than 120 degrees

Answer: (B)

When using a four-leg sling, the way the legs spread around the load determines how the lift is shared and how much tension each leg must carry. Keeping the diagonally opposite legs from opening too far keeps the vertical components of all leg tensions effective in lifting the load and preserves stable, balanced load paths.

If the angle between diagonally opposite legs grows beyond 90 degrees, the vertical lift contributed by each leg diminishes while the horizontal components push outward, causing higher tensions in the legs and increasing the chance of instability or side loading on the hardware. Keeping that diagonal angle at 90 degrees or less helps ensure the load is supported evenly and within the sling’s rated capacity.

The other options aren’t standard practical limits for this configuration: the angle can be at most 180 degrees in theory, a limit that isn’t the practical safety concern here; minimums like 30 degrees aren’t a typical constraint for four-leg slings, and a limit of 120 degrees is more conservative than typically required.