In communications cables, including Fiber optic cables, having the Transmission media wrapped helically around a central member, the longitudinal distance along the Cable required for one complete helical wrap; i.e. , the total cable length divided by the total number of wraps.

Note 1: In many fiber-optic cable designs, the lay length is shorter than in metallic Cables of similar diameter, to avoid overstressing the fibers during the pulling associated with the installation operation.

Note 2: The wraps, i.e. , turns, that are referred to should not be confused with the twists given twisted metallic pairs, i.e. , wires, to reduce electromagnetic coupling. Pairs of optical fibers are not given such twists. Synonym: pitch.