What is security mesh fencing?
Security mesh fencing uses rigid welded panels with deliberately narrow apertures that resist climbing and cutting. The benchmark is 358 mesh, named after the imperial dimensions of its aperture (3 x 0.5 inch). The small openings stop fingers and most hand tools gaining purchase, and heavy wire resists cutting - far more secure than standard welded fencing.
358 anti-climb mesh explained
358 mesh takes its name from a 3 inch x 0.5 inch aperture in 8 gauge wire. In metric terms the aperture is 76.2 x 12.7 mm. The narrow 12.7 mm opening is too small for fingers or footholds, making the panel very difficult to climb, while the welded grid resists spreading and cutting.
| Designation | Aperture (mm) | Aperture (inch) | Typical wire dia. |
|---|---|---|---|
| 358 mesh | 76.2 x 12.7 | 3 x 0.5 | 8 SWG (~4.0 mm) |
| 358 (heavy) | 76.2 x 12.7 | 3 x 0.5 | 6 SWG (~4.88 mm) |
| Double-wire 868 | 76.2 x 12.7 | 3 x 0.5 | 2 x 8 SWG horizontals |
Wire gauges and panel build
Security panels use heavy wire and small apertures, and are often supplied in single-wire (358) or double-wire (868) builds for added rigidity and cut resistance. Gauges below are given in SWG with metric equivalents.
| SWG | Diameter (mm) | Use in security mesh |
|---|---|---|
| 8 | 4.06 | Standard 358 panels |
| 6 | 4.88 | Heavy 358 panels |
| 4 | 5.89 | Maximum-security builds |
Anti-climb and anti-cut performance
- Anti-climb: the 12.7 mm aperture gives no toehold or finger grip, so the panel cannot easily be scaled.
- Anti-cut: heavy 8, 6 or 4 SWG wire and double-wire builds resist bolt croppers and hand tools.
- Anti-tamper: security panels are fixed with shrouded or one-way fasteners to resist removal.
- Rigidity: welded panels resist spreading and provide a clear sightline for surveillance.
Coatings and materials
- Galvanised steel: the base corrosion protection, usually hot-dip after welding.
- Galvanised plus polyester powder coat: a duplex finish for long outdoor life and colour - black and green are common.
- PVC-coated: an alternative polymer finish - see galvanised vs PVC.
Where security mesh is used and how to buy it
358 and high-security panels protect prisons, utilities, substations, data centres, airports, railways and commercial perimeters. Specify the mesh designation (358 or double-wire 868), wire gauge, panel height, post type and fixings, and the coating for the environment and required life. Confirm panel and post quantities and read the buying guide before ordering; for general perimeter work compare against standard fencing options.
Pair 358 panels with anti-tamper, shrouded fixings and the correct post system - the mesh is only as secure as the fasteners and posts holding it.