The normal recommendation for fiber optic cable is the minimum bend radius under tension during pulling is 20 times the diameter of the cable (d). Proper bend radius control ensures the integrity of optical performance and protects the glass. Minimize mechanical pressure on the outer sheath at crossing points: (armoured) cables crossing each other generate points of high pressure, so it is important when laying in figure 8 loops it is done in a correct way. While installers are aware of the fundamental importance of minimum bend radii, they often lack the practical know-how to. The fiber optic bend radius refers to the smallest radius a fiber cable can be bent without causing unacceptable signal degradation or physical damage. It is measured from the inside of the bend, not the outer curve.