72-core outdoor optical cable diameter

The outer diameter of a 72-core outdoor optical cable typically ranges from 8.5 mm to 12.8 mm, depending on construction and armor.Typical Cable Constructions and Diameters

• Standard steel-armored outdoor cable: According to Baudcom specifications, a 72-core outdoor fiber optic cable with a steel wire central strength member and PE outer jacket has an outer diameter of 12.8 ± 0.2 mm . The inner PE jacket alone measures 8.5 ± 0.2 mm . This type is suitable for direct burial and provides excellent crush and tensile resistance.
• Multi-loose tube outdoor cable: Belden's 72-fiber outdoor cable uses 6 loose tubes of 1.9 mm diameter each, with aramid yarns for strength and a PE outer jacket. The overall cable diameter is slightly larger than the sum of the tubes, typically around 10–13 mm, depending on filler and jacket thickness . This design is optimized for duct installation and structured outdoor networks.
• Reduced outer diameter cables: Some manufacturers, like Corning with their FREEDM® series, offer reduced-diameter 72-core cables for microduct applications. These cables can reduce the overall diameter by up to 25% compared to traditional loose tube designs, often resulting in diameters around 9–10 mm . These are ideal for high-density duct installations where space is limited.

Summary

The outer diameter of a 72-core outdoor optical cable depends on the cable type:

• Steel-armored, direct-burial: 12.8 mm
• Standard multi-loose tube: 10–13 mm
• Reduced-diameter microduct cable: 9–10 mm When selecting a cable, consider the installation environment, duct size, and mechanical protection requirements, as these factors influence the choice of cable construction and diameter.