Which knot is appropriate for connecting two ends of a sling?

The square knot is designed specifically for joining two ends of a rope or sling together securely. It is a reliable and easy-to-tie knot that can be used to create a fixed loop that won't slip under tension, making it ideal for tying two ends together. When properly tied, the square knot lays flat and distributes weight evenly, which is important in various applications, such as connecting slings or bundling materials.

Its effectiveness comes from the way it interlocks the two rope ends, providing a strong joint. This knot is most suitable when the two ends of the sling are of equal diameter and material. Proper tension and adjustment of the square knot will also ensure that it remains secure during use, avoiding any risk of uncoupling.

Other knots listed, while useful in certain scenarios, do not serve the same purpose as effectively as the square knot does for connecting two sling ends. The bowline creates a fixed loop that does not slip and is better suited for making loops at the end of a line; the figure-eight is often used for climbing and belaying but is not specifically designed for joining two ends. The sheepshank is primarily used for shortening a rope or taking up slack, rather than joining two ends together.