ASTM A392: Zinc Coating Classes, Mesh, and Selvage Rules

ASTM A392 is the U.S. material standard for zinc-coated steel chain-link fence fabric, and its current active version is A392-11a(2022).¹ It tells a manufacturer exactly what a compliant piece of galvanized chain-link mesh has to be: what steel, what zinc, what gauge, what mesh opening, what height, what edge finish, and what breaking strength. It does not cover the posts, rails, fittings, gates, or installation work that turn fabric into a fence. If you are writing a procurement spec, reviewing a submittal, or buying fencing you want to last, A392 is the document that governs the mesh itself.

What A392 Covers and What It Doesn’t

The standard applies to steel chain-link fabric that has been hot-dip galvanized either before weaving or after weaving.² It does not cover PVC- or vinyl-coated chain-link, which falls under ASTM F668, and it does not cover aluminum-coated fabric or any framework.³ If your project calls for colored mesh or for the posts and rails to meet a particular grade, you need other standards alongside A392.

The Six Things You Must Specify

A compliant order under A392 names six parameters. Leave any of them blank and the manufacturer defaults to the cheapest permissible option.

Mesh size
Wire size (gauge)
Fabric height
Selvage type at top and bottom
Zinc coating class
Breaking strength

Those same six items are what a mill certification report should document when the fabric is delivered.¹ Inspectors on commercial and government work routinely ask for that report before accepting a load.

Zinc Coating: Class 1 vs. Class 2

The coating class is the single biggest driver of how long the fence lasts. The zinc itself must conform to ASTM B6, in either Special High Grade or High Grade purity, so the coating bonds cleanly and resists premature oxidation.⁴ A392 then sets two coating weight classes:

Class 1: minimum 1.2 ounces of zinc per square foot of wire surface. Standard protection, suited to residential and light commercial use in mild climates.
Class 2: minimum 2.0 ounces of zinc per square foot. Intended for harsh environments, including industrial sites, coastal areas, and locations exposed to road salt.

Zinc corrodes at a roughly predictable rate, so the heavier coating translates directly into added service years. Specifying Class 1 in a coastal or industrial setting is an expensive mistake, because once rust shows the only remedy is replacement.

Galvanized Before Weaving vs. After Weaving

Hot-dip galvanizing happens in one of two sequences, and the choice interacts with the coating class.

Galvanized before weaving (GBW) dips individual wires in molten zinc and then weaves them into the diamond pattern. It is the more common method and is limited to Class 1, because wire with the heavier Class 2 layer is not widely produced.

Galvanized after weaving (GAW) weaves the fabric from bare steel and then dips the finished sheet. GAW is available in both Class 1 and Class 2, and it is the only route to Class 2 coating.²

Both methods are acceptable as long as the finished product meets the required coating weight and uniformity. The practical trap: if a spec calls for Class 2 without naming GAW, suppliers will push back because they cannot source Class 2 GBW wire. Specify both.

Wire Gauge, Mesh, and Height

The base metal is cold-drawn steel wire with a minimum tensile strength of 75,000 psi. A392 recognizes three standard gauges:

6 gauge: the heaviest, used for high-security perimeters such as correctional facilities and critical infrastructure. Minimum breaking strength 2,170 pounds of force.
9 gauge: the workhorse of commercial and industrial fencing. Minimum breaking strength 1,290 pounds of force.
11 gauge: lighter wire for residential and light-duty use. Minimum breaking strength 850 pounds of force.

Mesh size is the clear distance between parallel sides of the diamond. Options run from 2 inches down to 3/8 inch. Two-inch mesh covers most boundary fencing; 1-3/4 inch is common on tennis courts and anti-climb applications; openings under 1 inch are specialty products for animal enclosures and security screens.

Fabric heights run from 36 inches to 144 inches. A 48-inch fabric is typical for residential property lines, with 72 inches and taller standard on commercial and security jobs. Height drives the selvage requirement, so the two have to be chosen together.

Selvage Rules

Selvage is the finish of the wire ends at the top and bottom edges of the fabric. A392 recognizes two types.

Knuckled: the wire ends are looped back and closed, with the loop closed or nearly closed to a measurement less than the wire’s diameter. No sharp points remain.
Twisted: adjacent wire ends are twisted together in a tight helix and cut at an angle, leaving projecting ends at least 1/4 inch long. The result is an aggressive top edge.

The default rules under A392 are driven by safety. Fabric 60 inches and shorter gets knuckled selvage on both top and bottom. Fabric 72 inches and taller gets knuckled on one edge and twisted on the other, with the twisted edge typically at the top as a climbing deterrent.⁵ The standard explicitly warns against twisted selvage on fabric shorter than 72 inches. Fabric with mesh openings smaller than 2 inches must be knuckled on both edges regardless of height.

A392 does not define a “barbed” selvage. Barbed wire is a separate topping element installed above the fabric under different specifications and local building codes.⁵

Testing and Mill Certification

Two tests confirm compliance. The coating-weight test follows ASTM A90: a sample of wire is chemically stripped of its zinc, and the mass difference establishes the coating weight per unit area.⁶ The result must meet or exceed the minimum for the specified class, or the fabric is rejected.

The adhesion test wraps the coated wire tightly around a mandrel. If the zinc flakes, chips, or peels, the bond is inadequate. A good hot-dip process creates a metallurgical bond, not a mechanical one, and properly manufactured wire passes this easily.

Manufacturers document the results in a mill certification report (also called a mill cert or certified test report). A compliant report covers all six A392 conformance criteria.¹ If a contractor cannot produce one that matches the project spec, the material is subject to rejection on arrival.

Companion Standards for the Rest of the Fence

Because A392 governs only the fabric, a complete chain-link specification references several other standards:

ASTM F567 is the installation practice. It covers site prep, post setting, top rail and tension wire, tie wires and clips, fabric attachment, barbed wire, and gates.⁷
ASTM F626 covers fittings, including tension bars, tension bands, and brace bands, the hardware that pulls the fabric taut between terminal posts.⁸
ASTM F1083 and F1043 cover the steel pipe and tubing used for posts, rails, and gate frames. F1083 addresses schedule 40 galvanized pipe; F1043 classifies framework by coating type and application group.
ASTM F668 is the counterpart to A392 for PVC-coated chain-link fabric.³
ASTM B6 is the zinc purity standard that A392 references for the galvanizing material.⁴

Calling out A392 for the fabric but omitting F1083 for the posts leaves framework quality up to the contractor’s discretion, which rarely favors the buyer.

Writing a Spec That Holds Up

A few habits turn A392 from a reference into a usable procurement tool.

Always specify the coating class, galvanizing method, wire gauge, mesh size, fabric height, and selvage type explicitly. “Per ASTM A392” without the blanks filled in lets the manufacturer pick the cheapest default on every open parameter.

Require a mill certification report with every delivery, confirming compliance with all six conformance criteria. On larger jobs, require actual test values rather than a blanket statement of compliance.

Watch the GBW limit. A Class 2 requirement effectively mandates GAW fabric. A bid offering GBW against a Class 2 spec is either taking exception or ignoring the spec, and either case warrants scrutiny.

Finally, A392 is a material specification, not a performance warranty. It tells you what the fabric is when it leaves the mill. Service life depends on proper installation under F567, correct coating class for the environment, and ongoing care. The standard gives a reliable starting point; the rest is execution.

1
ASTM International. Standard Specification for Zinc-Coated Steel Chain-Link Fence Fabric
2
ASTM International. ASTM A392-11a(2017) – Standard Specification for Zinc-Coated Steel Chain-Link Fence Fabric
3
ASTM International. Standard Specification for Poly(Vinyl Chloride) (PVC)-Coated Steel Chain-Link Fence Fabric
4
iTeh Standards. ASTM B6-13 – Standard Specification for Zinc
5
iTeh Standards. ASTM A392-11a(2022) – Zinc-Coated Steel Chain-Link Fence Fabric
6
ASTM International. ASTM A90/A90M-21 – Standard Test Method for Weight [Mass] of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings
7
ASTM International. Standard Practice for Installation of Chain-Link Fence
8
ASTM International. Standard Specification for Fence Fittings