Which unit is used to express the thickness of fiber cable?

The thickness of fiber cable is commonly expressed in millimeters (mm). This unit is appropriate for measuring the outer diameter of various types of fiber optic cables, which can range from a few millimeters for simplex cables to larger diameters for armored or multi-fiber cables.

Using millimeters provides a clear and concise way to specify cable size, which is critical for determining compatibility with connectors, installation pathways, and other physical requirements within a cabling infrastructure.

Other units mentioned, such as feet, are more suitable for measuring lengths of cable rather than thickness. Microns (um) might be used in specific contexts relating to the diameter of the fiber core, but when discussing the overall structure of the cable, millimeters is the standard unit. Gigahertz refers to frequency and is not applicable to measuring thickness at all.