Barbed Wire

What's the difference between the core wire and the barb wire?

The core wire is thicker (2.0–3.5mm, high- or low-carbon steel) for tensile strength; the barb wire is thinner (1.0–2.5mm) and helically wrapped around the core at 50–150mm spacing.

Which surface treatment suits a coastal or humid site?

Hot-dip galvanizing (40–60μm coating) is rated for humid or coastal areas; electro-galvanizing (8–12μm) is intended for general dry environments only.