Fiber optic cable has a strict minimum bend radius, and sharp turns significantly increase friction and pulling tension. Instead of using 90-degree elbows, gentle, sweeping bends or specialized fittings should be utilized, especially where the conduit enters a building. stallers should consider bend radius, tension, jamming, and fill ratio before performing any conduit pull. Corning Optical Communications recommends the American Polywater® PULL-PLANNE able in conduit, observe the manufacturer's recommendations for maximum pulling tension and bend radius. The hair-thin glass cores within the cable are highly sensitive to physical stress and tight bending, which can cause signal loss or permanent damage.