Inside the Swage: What Really Happens to a 1x19 Wire Cable Under Pressure

When we talk about yacht rigging, we often focus on materials, tension settings, or corrosion, but we rarely stop to appreciate the invisible but vital process that keeps your standing rigging secure: swaging.

Swaging is the method used to permanently affix a terminal fitting (like a fork or eye) to a wire rope, and the image above offers a rare look inside a swaged 1x19 stainless steel cable. This is the real anatomy of a critical rigging joint—revealed by cutting through the swage and polishing it for inspection.

What Is Swaging?

Swaging involves inserting the wire into a machined terminal and then using a powerful hydraulic press to apply extreme pressure. This pressure plastically deforms both the terminal and the wire within, compressing them together into a single, solid unit. No welding. No adhesives. Just pressure—tons of it.

What Happens to the Wire?

The photo shows a cross-section of a swaged fitting on a 1x19 stainless steel cable. You can clearly see the internal wires have not just been squeezed—they've fused into one another, losing their original round shape. This is due to the immense radial pressure applied by the swaging machine, which forces the 19 individual wires into intimate contact with each other and the inner wall of the terminal. In some cases, the steel appears almost fluid-like in how it conforms and blends into adjacent strands. That's not melting—it's pure deformation.

This compression:

• Prevents slippage under load

• Distributes stress evenly through the fitting

• Provides maximum holding power with minimal bulk

Why Is This Important?

Poorly swaged terminals can lead to failure, especially if the pressure is uneven or the cable isn't fully inserted. Over time, movement inside the terminal (from vibration, cyclic loads, or corrosion) can weaken the connection.

That's why swaging must be done by trained professionals using calibrated machines. And why regular inspection of rigging—especially terminals—is crucial.

A Final Thought

Swaging is a mix of precision engineering and brute force. It's the silent hero of modern rigging—holding up tens of tons of sailing yacht under sail without anyone even noticing. Until, of course, something goes wrong.

This image is a great reminder of what's really going on inside your rig—out of sight but absolutely not out of mind.