What the 868 and 656 Numbers Mean
Double wire fencing gets its name from a simple but clever idea: two horizontal wires sandwich each vertical wire at every junction, creating an extremely rigid, anti-cut panel. The shorthand 868 and 656 describes the wire diameters in millimetres. An 868 panel uses 8 mm horizontal pairs (two 4 mm wires welded together) with 6 mm vertical wires, while a 656 panel uses 6 mm horizontal pairs with 5 mm verticals. The classic aperture is 200 x 50 mm, narrow enough to defeat finger and toe holds while staying transparent for surveillance. Because the welds are protected between the doubled wires, these panels resist the prying and peeling that plague single-wire mesh, which is exactly why they dominate commercial, industrial and utility perimeters across Europe and the Gulf. At Zhongman we manufacture both grades to order, matching wire gauge and aperture to the threat level a project actually faces.
Panel Construction and Standard Sizing
A double wire panel is a welded-mesh sheet, not a roll, which is what gives it dimensional stability. Standard panel width is 2500 mm, with heights from 630 mm up to 2430 mm and beyond for high-security lines. Most panels carry V-shaped horizontal bends, or beams, pressed into the sheet to add stiffness against impact and climbing leverage. Posts are typically rectangular 60 x 40 mm or 60 x 60 mm hollow sections, drilled or slotted to accept clamp bars that trap the panel against the post. The 200 x 50 mm aperture is the workhorse, but tighter 50 x 50 mm or 100 x 50 mm versions exist for anti-climb applications near schools, prisons and substations. We supply panels, posts, clamps, security fasteners and toppings as a coordinated kit, pre-drilled to your post centres so installers spend time bolting rather than improvising on site.
Coatings and Corrosion Protection
The lifespan of a double wire fence is decided at the coating stage, long before it leaves the factory. The baseline is hot-dip galvanizing, where zinc bonds metallurgically to the steel and self-heals minor scratches. For coastal, industrial or chemically aggressive sites we recommend our Galfan zinc-aluminium alloy, which delivers two to three times the salt-spray endurance of pure zinc at the same coating weight. On top of that, a polyester powder coat or PVC layer adds a colour finish, RAL 6005 green and RAL 9005 black being the most requested, plus a second moisture barrier. The sequence matters: galvanize first, then coat, so the polymer locks the zinc in. Zhongman runs both galvanizing and powder lines in-house, so we control coating thickness and can certify it rather than relying on a third party.
Where Double Wire Fencing Outperforms
Double wire panels earn their premium in settings where a breach is expensive or dangerous. Data centres, electrical substations, water treatment works, logistics yards and airport landside areas all favour 868 systems because the rigidity resists vehicle nudging and the narrow aperture frustrates cutting with hand tools. The transparency is a security feature in its own right: guards and cameras see straight through, leaving nowhere to hide. Compared with welded panel mesh of single-wire construction, the doubled horizontals roughly double the cut-through time, and compared with chain link, there is no slack to lift or peel. Where the threat is lower, such as parks, car parks and light commercial boundaries, the lighter 656 grade gives most of the look and stiffness at a friendlier price, which is why we keep both in active production.
Specifying and Sourcing for Export
When you write a double wire specification, pin down five things: grade (868 or 656), panel height, aperture, coating system with minimum thickness, and post type with the matching clamp and security bolt. Add the standard you want the welds and zinc to meet so the supplier cannot quietly downgrade. For overseas projects, packing and documentation are as critical as the steel itself; loosely stacked panels arrive bent and unusable. Zhongman palletises panels with edge protection and steel strapping for safe container loading, and provides mill certificates, coating test reports and full ASTM or EN references with every shipment. If you are comparing quotes or need a sample panel before committing a tender, send us your drawings and site conditions and our engineers will return a costed, compliant specification you can build straight from.