Chain Link Fence Specification Guide: Wire Gauge, Mesh and Coating Explained
Specify chain link properly: 50 mm mesh, 2.68 mm wire, 240 g/m² zinc, 60 mm posts at 2.5 m. Includes gauge-to-mm tables, coating lifespan data, ASTM/EN standards and a paste-ready RFQ template.
Five numbers define a chain link fence
Ask any fence contractor what a chain link fence costs and the honest answer is: which one? A 1.8 m high boundary fence in 2.5 mm galvanized wire and a 3.0 m sports fence in 3.0 mm PVC-coated wire differ by a factor of three, and they are the same product family.
These are the five numbers that decide both performance and price:
| Parameter | Range we manufacture | Typical choice |
|---|---|---|
| Mesh aperture | 25–100 mm | 50 mm (2") for boundary; 45–50 mm for sports |
| Wire diameter | 1.6–4.0 mm | 2.5–3.0 mm for security, 2.0 mm for light duty |
| Coating | Hot-dip galvanized / Galfan / PVC over zinc | 240 g/m² zinc interior; PVC coastal |
| Height | 1.0–4.0 m | 1.8–2.4 m boundary; 3.0–4.0 m sports and industrial |
| Post & rail | 48–89 mm OD, 1.5–4.0 mm wall | 60 mm post, 38 mm top rail, 2.5 m spacing |
If you specify those five and nothing else, you will get a fence that works. If you specify "2 inch chain link, standard," you will get whatever the cheapest interpretation of "standard" is — and that is how buyers end up with a fence that sags after two winters.
Mesh aperture: smaller is stronger and more expensive
| Aperture | Common name | Best for | Relative cost per m² |
|---|---|---|---|
| 25 mm | 1" | Aviaries, high-security, ball containment | 1.45× |
| 40 mm | 1-1/2" | Sports courts, schools | 1.20× |
| 50 mm | 2" | Boundary, industrial, general purpose | 1.00× |
| 57 mm | 2-1/4" | Export markets, light boundary | 0.95× |
| 63 mm | 2-1/2" | Temporary, agriculture | 0.88× |
| 75 mm | 3" | Temporary fencing, crowd control | 0.82× |
Aperture works two ways. Smaller mesh resists cutting and climbing better, and it stops a football passing through — which is why sports fencing uses 45–50 mm rather than 63 mm. It also uses more wire per square metre for the same wire diameter, because the diamond pattern has more turns.
For general boundary duty, 50 mm is the right answer almost everywhere. The exception is a very large perimeter where the client wants the lowest capital cost and accepts a lighter fence — there, 57–63 mm is legitimate.
Wire diameter: the number suppliers fudge most
Chain link is sold by "gauge," and gauge is the single most abused term in the trade. British Standard Wire Gauge (SWG), US Steel Wire Gauge and the Chinese export convention all differ, and some suppliers simply quote a gauge that corresponds to nothing.
Ignore gauge. Specify millimetres and verify with a micrometer.
| Nominal gauge | Actual diameter (mm) | Wire mass (approx., kg/m² at 50 mm) | Typical use |
|---|---|---|---|
| 6 G | 4.88 | 3.10 | Prison, high security |
| 9 G | 3.66 | 1.75 | Sports fencing, industrial |
| 10 G | 3.25 | 1.38 | Heavy boundary |
| 11 G | 3.05 | 1.21 | Security boundary |
| 11.5 G | 2.95 | 1.14 | Standard security |
| 12 G | 2.68 | 0.94 | General boundary |
| 12.5 G | 2.50 | 0.82 | Light boundary |
| 14 G | 2.03 | 0.54 | Temporary fence panels |
The gap between 2.5 mm and 2.68 mm sounds trivial and is 13% of the steel. On a 500 m perimeter, 1.8 m high, that is about 120 kg of wire — real money, and invisible once installed.
Test on arrival: measure ten random points on the mesh with a micrometer, not the selvedge. The selvedge (edge) wire is usually one gauge heavier than the body wire, and suppliers sometimes measure that instead.
Coating: what actually determines lifespan
| Coating | Zinc mass | Life, rural | Life, coastal | Relative cost |
|---|---|---|---|---|
| Electro-galvanized | 20–40 g/m² | 4–8 years | 2–4 years | 0.85× |
| Hot-dip galvanized, standard | 240 g/m² | 25–35 years | 12–18 years | 1.00× |
| Hot-dip galvanized, heavy | 275 g/m² | 30–45 years | 18–25 years | 1.08× |
| Galfan (Zn-5% Al) | 255 g/m² | 35–50 years | 20–30 years | 1.15× |
| PVC over 240 g/m² zinc | 240 g/m² + 0.4–0.6 mm | 40+ years | 30–40 years | 1.30–1.45× |
Three points that buyers get wrong:
PVC is a topcoat, not a substitute for zinc. Good PVC-coated fence has 240 g/m² of hot-dip zinc under the plastic. Cheap PVC-coated fence has a thin electro-galvanized layer underneath, and once the plastic is scratched — which happens during installation — the wire rusts through from the inside within a few years. Ask for the zinc mass underneath the PVC, in writing.
PVC thickness matters. 0.4 mm is standard; 0.5–0.6 mm is marine grade. Below 0.35 mm the coating is mostly colour, not protection.
Colour affects heat and UV. Green and black PVC are the most UV-stable formulations. Bright colours fade measurably in 5–8 years in high-UV climates, which is a cosmetic issue, not a structural one — but clients notice.
Posts, rails and spacing
The fabric is only half the fence. A 2.68 mm mesh on a 1.5 mm wall post will sag; a 2.5 mm mesh on a 2.5 mm wall post will not.
| Fence height | Line post OD / wall | Top rail OD / wall | Post spacing | Bottom rail |
|---|---|---|---|---|
| 1.2 m | 48 mm / 1.5 mm | 32 mm / 1.5 mm | 3.0 m | Optional |
| 1.5 m | 48 mm / 1.8 mm | 38 mm / 1.5 mm | 3.0 m | Optional |
| 1.8 m | 60 mm / 2.0 mm | 38 mm / 1.8 mm | 2.5–3.0 m | Recommended |
| 2.1 m | 60 mm / 2.0 mm | 42 mm / 2.0 mm | 2.5 m | Yes |
| 2.4 m | 76 mm / 2.5 mm | 42 mm / 2.0 mm | 2.5 m | Yes |
| 3.0 m (sports) | 76 mm / 3.0 mm | 48 mm / 2.5 mm | 2.5 m | Yes |
| 4.0 m (industrial) | 89 mm / 3.0 mm | 48 mm / 3.0 mm | 2.5 m | Yes |
Corner, end and gate posts take roughly 1.5× the load of a line post and should be at least one size up, set in a concrete footing 300 mm diameter × 600–900 mm deep depending on soil and wind load.
Post spacing beyond 3.0 m is false economy. The fabric sags between posts, the top rail bows, and the fence looks tired within a year.
The standards worth citing
If you are writing a specification and want it to be enforceable, cite these:
- ASTM A392 — zinc-coated steel chain-link fence fabric. Defines the zinc coating class and the breaking strength of the wire.
- ASTM A817 — metallic-coated steel wire for chain-link fabric and tension wire.
- ASTM F567 — standard practice for installation. Covers post embedment, tensioning and tolerances.
- ASTM F1043 — strength and coating requirements for steel fence framework (posts and rails).
- EN 10223-4 — European standard for steel wire chain-link fencing.
- BS 1722-1 — UK standard, widely referenced in Commonwealth markets.
A quote that says "meets ASTM A392" without stating the coating class has told you nothing. The standard covers multiple classes from 60 g/m² to 275 g/m², which is a 4.5× spread in lifespan.
Reading a Chinese quote
Four phrases appear in almost every chain link quotation from China, and each one hides a decision:
"Standard galvanized." Ask for the zinc mass in g/m² and the test method. If the answer is not a number, the answer is 40–60 g/m².
"Hot-dipped." Sometimes true, sometimes the wire is drawn from pre-galvanized rod, which gives a thinner, less uniform coating. The giveaway is the price: genuine 240 g/m² hot-dip is 15–25% above the pre-galvanized version.
"2 inch mesh, 12 gauge." Which gauge? Ask for the millimetre figure, then check it against the table above.
"FOB, post and rail included." Confirm the post wall thickness and whether caps, tension bands, brace bands and tension wire are in the price. These fittings are 8–15% of a fence order and are routinely stripped out to make a quote look competitive.
A specification template you can paste into an RFQ
Chain link fence fabric: 50 mm mesh, 2.68 mm body wire, 3.66 mm selvedge, hot-dip galvanized to 240 g/m² minimum (ASTM A392 Class 1 or EN 10223-4), supplied in 2.5 m high rolls.
Framework: line posts 60 mm OD × 2.0 mm wall; corner/end posts 76 mm OD × 2.5 mm; top rail 42 mm OD × 2.0 mm; all hot-dip galvanized to 275 g/m² (ASTM F1043).
Fittings: tension bands, brace bands, post caps, carriage bolts, tension wire, all galvanized to match.
Installation: post spacing 2.5 m, post embedment 600 mm in concrete, fabric tensioned to ASTM F567.
Quantity: ___ m linear, ___ gates of ___ m width.
That paragraph removes every assumption a supplier could otherwise make in their favour.
Our chain link range covers 25–100 mm apertures in galvanized, Galfan and PVC coated finishes, with matching framework and fittings. For a quote against the specification above, send the linear metres, the height and the destination port to our team.
Frequently asked questions
What is the best wire gauge for a chain link fence?
For a boundary fence, 2.5–2.68 mm (roughly 12–12.5 gauge) hot-dip galvanized is the practical minimum. For security or sports use, 2.95–3.05 mm. Below 2.0 mm the fence is a visual barrier, not a physical one.
How long does a galvanized chain link fence last?
25–35 years inland with 240 g/m² zinc; 12–18 years in a coastal atmosphere. With PVC over 240 g/m² zinc, expect 30–40 years on a coast. With electro-galvanized wire, 4–8 years.
Is PVC coated chain link better than galvanized?
Only when there is proper hot-dip zinc underneath. PVC gives colour, extra abrasion resistance and a second barrier against salt. Over a thin electro-galvanized core it is worse than plain galvanized, because the plastic traps moisture at every scratch.
How far apart should fence posts be?
- 5 m for heights of 1.8 m and above; 3.0 m is acceptable up to 1.5 m with a top rail. Wider spacing always costs more in the long run through sag and rail deflection.
What is the difference between 50 mm and 63 mm mesh?
Both are "chain link". 50 mm uses about 20% more wire per m², resists cutting better, and stops a ball. 63 mm is cheaper and common in agriculture and temporary fencing, where the fence only needs to be a deterrent.
