Webbing is often used to builds rappels, extend protection, and occasionally for mountain rescue operations. But not all webbing is created equal—and how long it lasts in the wild depends heavily on what it’s made of, and how much time it’s spent soaking up the sun.
Climbing-specific (“climb spec”) tubular webbing and military-spec (“mil spec”) tubular webbing are the two most common types found in climbers’ packs. Both are typically made from nylon and share similar nominal breaking strengths in the neighborhood of 4,000 pounds (around 18 kN). The difference lies in the weave. Climb spec webbing is designed for flexibility and knotability—it feels soft, supple, and easy to manipulate. Mil spec webbing, on the other hand, is woven tighter and denser to meet military durability standards. It’s stiffer, more abrasion-resistant, slightly heavier and harder to tie knots in.
Regardless of type, all nylon webbing has a common enemy: ultraviolet (UV) radiation. Over time, exposure to sunlight breaks down nylon fibers at a molecular level, dramatically reducing strength. Studies and drop tests have shown that heavily sun-bleached webbing can lose over 50% of its original strength in its first three years. In desert or alpine environments where gear bakes day after day, this is a serious concern.
Climb spec webbing—because it’s looser woven—tends to show UV damage sooner, with fading and fraying more visible. Mil spec webbing’s tighter weave offers a bit more protection, but not immunity. If your slings look dull, crispy, or faded, they’re due for retirement.
Ultimately, webbing is cheap insurance. Whether climb spec or mil spec, replace anything that shows any sign of fading. The sun may feel good on your back, but it’s horrific on your webbing and slings.