How thick is a 24-core indoor single-mode optical cable

A typical 24-core indoor single-mode optical cable has an outer diameter of approximately 7.5 mm.

Cable Construction and Dimensions

A 24-core indoor single-mode cable generally consists of:

• Single-mode fibers with a core/cladding diameter of 9/125 µm .
• Tight-buffered fibers with a 900 µm coating for indoor handling and protection .
• All-dielectric construction with optional LSZH (low smoke zero halogen) jackets for fire safety in indoor environments .
• Outer diameter: Around 7.5 ±0.3 mm for standard 24-core indoor cables . This diameter allows the cable to be installed in trunking, underfloor, or ceiling spaces without excessive bulk, while maintaining flexibility for routing and termination.

Additional Considerations

• Jacket material: LSZH is common for indoor use to reduce smoke and toxic gas in case of fire.
• Mechanical protection: Some cables include aramid yarn strength members for tensile strength, while others rely on the tight-buffered design for durability .
• Installation environment: Indoor cables are optimized for short runs and easy handling, whereas indoor/outdoor variants may include water-blocking and UV resistance . In summary, when planning for installation, a 7.5 mm outer diameter is typical for a 24-core indoor single-mode optical cable, with slight variations depending on manufacturer and specific design features.