40 mesh denotes 40 wires per inch in each direction. For gas appliance burner & flame arrestor mesh the governing document is EN 437 / ANSI Z21 appliance; the specification row, aperture-micron conversion and selection guidance for this count follow.
40 Mesh Specification Row (EN 437 / ANSI Z21 appliance)
| Mesh count | Wire diameter (mm) | Aperture (mm) | Micron rating (u00b5m) | Open area (%) | Material |
|---|---|---|---|---|---|
| 40-Mesh | 0.220 | 0.415 | 415 | 42.0 | SS310S |
40 Mesh to Micron & Aperture
| Openings per inch | 40 |
|---|---|
| Aperture (opening width) | 0.39 mm |
| Micron rating | 385 µm |
| Standard wire diameter | 0.25 mm |
| Open area | 36.8 % |
Aperture = (25.4 mm ÷ mesh count) − wire diameter. The micron rating equals the aperture in micrometres; actual retention also depends on particle shape and cake formation.
Wire Diameter Options at 40 Mesh
| Option | Wire dia | Aperture | Micron | Open area | Weight (SS) |
|---|---|---|---|---|---|
| Heavy wire | 0.325 mm | 0.310 mm | 310 µm | 23.8 % | 2.18 kg/m² |
| Standard wire | 0.250 mm | 0.385 mm | 385 µm | 36.8 % | 1.29 kg/m² |
| Fine wire | 0.188 mm | 0.448 mm | 448 µm | 49.7 % | 0.72 kg/m² |
Heavier wire adds strength and abrasion life but closes the aperture; finer wire opens the aperture and raises throughput at the cost of durability. Specify mesh count AND wire diameter to fix the aperture unambiguously.
Open Area & Flow at 40 Mesh
The standard 40 mesh weave presents an open area of about 36.8%. At this count the mesh presents little flow resistance; selection is normally driven by particle retention and mechanical strength rather than pressure drop.
40 Mesh Cloth Weight
Standard 40 mesh stainless cloth weighs approximately 1.29 kg/m² (density 7.93 g/cm³ basis; brass and copper weave roughly 10% heavier, aluminum about one third). Use this figure for roll handling and freight estimation.
Typical Applications for 40 Mesh Gas Appliance Burner & Flame Arrestor Mesh
40 mesh gas appliance burner & flame arrestor mesh is commonly specified for general straining and sieving, paint and coating filtration, grease filters, insect screening, grain cleaning and pre-filtration ahead of fine media.
Plain, Twill or Dutch Weave at This Rating?
Plain square weave is the standard at this count: every opening is a true square of the stated aperture, retention is absolute for hard spherical particles, and the cloth is easy to clean.
What Gas Appliance Burner & Flame Arrestor Mesh Does
Forming the flame surface of premix gas burners and the flashback screens inside gas appliances.
Fitting & Care
- Install with even tension so the flame front stays uniform.
- Inspect for oxidation and holes at service.






