Special steel wire for fiber optic cables

Steel wires in fiber optic cables provide structural support, mechanical protection, and corrosion resistance, with types including messenger strands, lashing wires, and steel wire armoring (SWA). Types of Steel Wire in Fiber Optic Cables1.

Messenger Wire/

Strand Messenger wires are stranded steel cables that support the weight of aerial fiber optic cables. They typically consist of six wires wrapped around a central wire, most commonly made of carbon steel with a zinc or zinc-aluminum coating for corrosion protection. Coating classes (A, B, C) indicate the thickness of the protective layer, with zinc-aluminum coatings offering superior resistance in harsh environments such as coastal areas.

Messenger wires are specified by diameter and tensile strength to match the load requirements of the fiber installation. 2. Lashing Wire Lashing wires are stainless steel wires used to secure fiber optic cables to messenger strands.

They are annealed for high ductility and have minimum tensile strengths of 70–90 kpsi. Common stainless steel grades include: 430: General use in ordinary atmospheric conditions302: Higher tensile strength for corrosive environments316: Maximum corrosion resistance for severe conditions, including chlorides and sulfides The diameter of lashing wire is typically 0. 038" to 0.

045", and the required length depends on the cable bundle size. 3. Steel Wire Armored (SWA) Cable SWA cables incorporate steel wire armoring between the inner sheath and outer jacket, providing protection against crushing, impact, rodent attacks, and environmental hazards.

This design is ideal for direct burial or outdoor installations. The steel wire layer absorbs mechanical stress, preventing bending or microbending that could degrade optical performance.

SW

A cables often include additional protective layers such as Kevlar yarn and water-blocking gels or powders, with a UV-stable outer sheath for long-term durability. 4. High Strength Steel Wire (HSSW) Armored Cable HSSW armored fiber optic cables use galvanized plow steel armor to enhance mechanical performance.

Compared to traditional steel tape armored cables, HSSW offers: Nearly ten-fold improvement in tensile strengthTwo-fold improvement in crush resistanceThree-fold improvement in impact energy resistance These cables are suitable for industrial, pipeline, oil and gas, and harsh environmental applications, meeting Telcordia GR-20-Core standards.

Key Considerations

When selecting steel wire for fiber optic cables, consider: Corrosion protection: Choose appropriate coatings or stainless steel grades based on environmental exposureMechanical strength: Ensure tensile strength matches cable weight and installation spanInstallation type: Aerial, direct burial, or industrial applications may require different wire typesCable bundle size: Determines lashing wire length and messenger strand specificationsStandards compliance: ASTM standards (e.g., ASTM 475 for metallic-coated strands, ASTM A228 for optical cable wires) ensure consistent quality and performance. Steel wires are essential for maintaining the structural integrity and longevity of fiber optic networks, providing both support and protection against environmental and mechanical stresses.