What is expanded metal?
Expanded metal is formed from a single sheet of steel, aluminium or stainless that is simultaneously slit and stretched, opening thousands of diamond-shaped apertures without removing any material. Because it is one continuous piece with no welds, it is strong for its weight and cannot unravel. It differs from woven and welded mesh and from perforated sheet - see mesh vs expanded vs perforated.
How the diamond pattern is measured
Each diamond is defined by two dimensions: the long way of the diamond (LWD) and the short way of the diamond (SWD), plus the strand width and thickness. These describe the aperture and the strength of the mesh.
| Term | Meaning |
|---|---|
| LWD | Long way of diamond - the longer aperture dimension |
| SWD | Short way of diamond - the shorter aperture dimension |
| Strand width | Width of the metal strand forming the diamond |
| Strand thickness | Thickness of the original sheet |
Raised vs flattened
- Raised (standard) expanded: strands sit at an angle, giving a three-dimensional, non-slip surface - ideal for walkways, ramps and treads.
- Flattened expanded: the raised mesh is cold-rolled flat for a smooth, level surface - used for facades, infill panels, shelving and where a flush finish is needed.
Standard vs heavy grades
| Grade | Typical SWD x LWD (mm) | Typical thickness (mm) | Common use |
|---|---|---|---|
| Light / fine | 6 x 12 - 10 x 25 | 0.8 - 1.5 | Guards, filters, ventilation |
| Standard | 20 x 50 - 28 x 60 | 1.5 - 3.0 | Fencing, infill, facades |
| Heavy | 34 x 76 - 60 x 130 | 3.0 - 6.0 | Walkways, platforms, security |
Materials
- Mild steel (galvanised or painted): the economical general-purpose choice for fencing, guards and grating.
- Stainless steel (SS304 / SS316): for corrosion resistance and architectural finishes.
- Aluminium: lightweight and corrosion-resistant for facades, cladding and trailer floors.
Where expanded metal is used
- Walkways, stair treads and platform flooring with anti-slip raised mesh.
- Security - window guards, cages, anti-climb screens and infill panels.
- Architecture - facades, sunshades, ceilings and decorative cladding.
- Industrial - machine guards, filters, shelving and battery plates.
How to choose and buy expanded metal
Choose raised mesh for grip and load-bearing surfaces and flattened mesh for flush finishes. Select the diamond size for the open area you need and the sheet thickness for strength. Specify material and finish for the environment, and confirm full sheet dimensions and quantity. Estimate weight with the weight calculator before ordering.
Because expanded metal is a single sheet with no welds, it will not unravel if cut - handy for custom panel sizes, though cut strands can be sharp.