Security mesh fencing is welded high-tensile panel fencing with very small apertures - notably 358 mesh at 76.2 x 12.7 mm - designed so fingers and tools cannot grip or cut it, used for prisons, utilities, data centres and critical infrastructure.
By the WireMeshQA editorial team · Independent wire mesh reference
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.
Figure summary: 358 (anti-climb) security mesh uses very narrow rectangular apertures — about 12.7 by 76.2 mm — that give no finger-holds and resist the insertion of cutting tools. Combined with a rigid welded structure, it is used for high-security perimeter fencing around utilities, prisons and infrastructure.
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.
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.
Tip
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.
Frequently asked questions
What is 358 security mesh?
358 mesh is a high-security welded panel named after its aperture of 3 x 0.5 inch in 8 gauge wire, which is 76.2 x 12.7 mm in 8 SWG (about 4 mm). The narrow opening gives no finger or foothold for climbing and the heavy welded wire resists cutting, making it a standard for prisons and critical infrastructure.
Why is 358 mesh called anti-climb fencing?
It is called anti-climb because the 12.7 mm vertical opening is too narrow to insert fingers or a toe, leaving no grip or foothold to scale the fence. Combined with rigid welded panels and heavy wire that resists cutting, this makes 358 mesh very difficult to climb or breach without tools and time.
What wire gauge is used in security mesh fencing?
Standard 358 panels use 8 SWG wire (about 4.06 mm). Heavier security builds use 6 SWG (around 4.88 mm), and maximum-security panels can use 4 SWG (around 5.89 mm). Double-wire 868 panels pair two horizontal wires for added rigidity and cut resistance. Heavier gauges improve anti-cut performance.
What is the difference between 358 and 868 mesh?
Both share the 76.2 x 12.7 mm aperture, but 358 uses single horizontal wires while 868 (double-wire) uses two horizontal wires either side of the verticals. The double-wire build is more rigid and harder to cut, giving higher anti-cut and anti-tamper performance for the most demanding security perimeters.
Where is security mesh fencing used?
Security mesh fencing protects high-risk and critical sites such as prisons, electrical substations, utilities, data centres, airports, railways, military bases and commercial perimeters. It is chosen where standard fencing is not enough to resist climbing, cutting and tampering, and is usually paired with anti-tamper fixings and a matching high-security post system.
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