On slings, a well made splice retains up to 90% of the strength of the rope, while a knot retains only

• A. 25 percent
• B. 75 percent
• C. 50 percent or less
• D. 60 percent

Answer: (C)

Understanding how you terminate rope used in slings is key to keeping the rig safe. A splice keeps most of the rope’s strength by distributing the load along the strands with little fiber damage, so you can approach about 90% of the original strength. A knot, however, creates sharp bends and friction that crush or fray the fibers, concentrating stress and reducing the rope’s capacity. The general rule of thumb is that a knot can leave you with about half or less of the rope’s strength, depending on the rope material and the knot used. So the best general guideline here is fifty percent or less. This is why knots are much weaker for critical load applications, and splices are preferred when you need to preserve strength.