What is the efficiency percentage of a square knot?

The efficiency percentage of a square knot is recognized as being approximately 60%. This is due to the way a square knot performs under load and how effectively it holds two ropes of similar diameter together. When tied correctly, a square knot can retain much of the tensile strength of the rope, but it does have a tendency to slip and can jam tightly under load, which contributes to its efficiency being somewhat limited compared to other types of knots.

The efficiency refers to the percentage of the rope's original strength that is retained after tying the knot. A square knot is often used for joining two lines or securing packages, but it is important to note that it is not as reliable in all conditions, particularly if the ropes are of different materials or sizes. Always considering the specific application and the types of materials being used is crucial to ensure safety and effectiveness in rigging scenarios.