The steel used in SWA cables is not high-carbon tool steel, nor is it brittle cast iron. It is specifically low-carbon (mild) steel wire, typically containing less than 0.25% carbon.

So what exactly does “correct” installation entail? Where do standards draw the line between best practice and code compliance? And why is grounding not just an electrical formality—but a foundational requirement for safety, reliability, and longevity?

In a market where “SWA” can be loosely applied to substandard products, how do you ensure the cable you’re purchasing will truly perform as expected over its 25+ year design life? Verification isn’t optional—it’s essential. And it must happen before the cable leaves the factory, not after it fails in the field.

The core working principle is mechanical decoupling. The optical fibers inside an SWA cable never bear load, never touch metal, and never experience strain—even when the outer armor is bent, crushed, or stretched.

At the heart of every SWA cable are the glass fibers themselves—typically ITU-T G.652.D single-mode for telecom and utility applications, or occasionally OM4/OM5 multimode for short-reach industrial links.

9/125 µm: A single-mode fiber (SMF) with a 9 µm core and 125 µm cladding. 50/125 µm: A multimode fiber (MMF) with a 50 µm core and 125 µm cladding.