Rope manufacturers and top climbing rope brands go through rigorous tests and quality assurance checks to ensure redundancy, load-bearing strength, and climber safety. Rock climbing ropes, different from arborist or other static ropes used in rope access, are dynamic and stretch under load. Ropes with greater diameter typically have greater load-bearing capacity. Longer ropes, in general, typically are stronger than shorter ropes due to the nature of elasticity. Most single ropes can withstand an impact force of 20-30kN. Half ropes and twin ropes on the other hand are much thinner and lighter, and can only take an impact force of 5-10kN.