Chain link fence: mesh, wire and fittings

What a chain link fence is

The Chain Link Fence Manufacturers Institute (CLFMI), the trade body of chain link makers, defines chain link fabric as wire “helically wound and interwoven” into a continuous mesh, with no knots or ties. Each wire spirals down the roll and hooks into the one beside it. At the top and bottom edge, called the selvage, pairs of wire ends are either bent back into a tight loop (knuckled) or twisted together.

The source used throughout this page is the CLFMI Product Manual CLF-PM0610, updated in March 2017. It refers to ASTM standards for each part, but the figures below come from the manual itself.

Chain link mesh sizes and wire gauges

Mesh size is measured as the clear distance between two parallel wires of one opening, not from corner to corner. The wire is sold by gauge: the higher the number, the thinner the wire.

Chain link mesh sizes and wire gauges

Mesh size	Wire gauge	Wire diameter	Use given by CLFMI
54 mm (2⅛ in)	11½	2.87 mm	residential
50 mm (2 in)	11	3.05 mm	residential, light commercial
50 mm (2 in)	9	3.76 mm	residential, commercial, industrial
50 mm (2 in)	6	4.88 mm	commercial, industrial, security
44 mm (1¾ in)	11	3.05 mm	tennis courts
44 mm (1¾ in)	6	4.88 mm	security
32 mm (1¼ in)	11	3.05 mm	residential, swimming pools
25 mm (1 in)	9	3.76 mm	heavy industrial, security

Source: CLFMI Product Manual, Table 3.

For security fencing, the manual adds small mesh of 9, 13 and 16 mm. Its Table 1 gives breaking strengths of 3,340–3,780 N for 9 gauge wire and 1,690–2,890 N for 11 gauge, so a gauge step changes strength as well as weight.

Chain link wire coatings

CLFMI names four kinds of fabric by coating:

• Galvanised — zinc-coated fabric to ASTM A392.
• Aluminium-coated — ASTM A491.
• Zinc-5% aluminium-mischmetal alloy — ASTM F1345.
• Polymer-coated — a plastic layer over metal-coated wire, to ASTM F668, in colours from ASTM F934.

On polymer-coated chain link wire the stated gauge is the steel core, not the finished thickness. The coating itself adds 0.38–0.64 mm in the heavier classes (1 and 2a) and 0.15–0.25 mm in class 2b, according to the manual’s Table 2. A polymer-coated roll and a galvanised one of the same stated gauge have the same steel core diameter.

Parts of a chain link fence

Parts of a chain link fence

Part	What the CLFMI specification says
Line posts	intermediate posts, no more than 3.05 m (10 ft) apart
Terminal posts	end, corner, gate and pull posts where the fabric is fixed; braced and trussed on fences 1.8 m (6 ft) and higher
Top rail	6.4 m (21 ft) lengths running through the post tops, joined with sleeves at least 152 mm long; a mid rail on fences 3.66 m and higher
Tension wire	7 gauge (4.50 mm), stretched before the fabric, 102 mm above its bottom edge; and 102 mm below the top where there is no top rail
Tension bar	galvanised steel bar 50 mm shorter than the fabric height, threaded through its end and fixed to the terminal post with tension bands
Ties and hog rings	9 gauge (3.76 mm) aluminium alloy for standard fences; galvanised steel where more security is needed
Barb arms	at the post tops, for three strands of barbed wire at 45° or vertical, or six strands on a V-shaped arm

Barbed wire is stretched between terminal posts and sits in the slots of the barb arms. For the wire itself, see barbed wire.

Setting the posts

The CLFMI specification sets posts plumb in concrete with a 28-day strength of 17.2 MPa. The footing goes at least 610 mm deep, plus 76 mm for every 305 mm of fence height over 1.22 m. For a 1.83 m (6 ft) fence that comes to about 762 mm — our calculation from the manual’s rule.

• Footing width: at least four times the post’s outside diameter for posts up to 101.6 mm, and three times for larger posts.
• Footing top: crowned so that water runs away from the post.
• Gates: clear the ground by 76 mm where the ground allows, with no more than a 76 mm gap at the hinge and latch side when closed.

The manual adds that soil, wind load and fence height may call for larger or deeper footings than these minimums.

What to check when you buy chain link wire

1. Mesh size and gauge together. A quote for “chain link 2 inch” is incomplete without the wire gauge or diameter in millimetres.
2. Coating type. Ask whether the wire is galvanised, aluminium-coated or polymer-coated, and for polymer, the gauge of the steel core.
3. Roll height and length. Check them against the line of the fence and the height of the posts.
4. Selvage. CLFMI’s standard for 50 mm mesh 1.8 m high and over is one knuckled edge and one twisted edge.
5. Fittings in the same finish. Ties, bands and tension bars should match the fabric coating; CLFMI asks for polymer-coated fittings in the fence colour.

Chain link fence in Zanzibar

Kitovu sells from stock in Zanzibar, and chain link wire is not among its products. For other fencing materials, see types of wire mesh, welded mesh and the electric fence guide.