20 mesh denotes 20 wires per inch in each direction. For plain weave wire mesh the governing document is ISO 9044 / ASTM E2016; the specification row, aperture-micron conversion and selection guidance for this count follow.
20 Mesh Specification Row (ISO 9044 / ASTM E2016)
| Mesh count | Wire diameter (mm) | Aperture (mm) | Micron rating (u00b5m) | Open area (%) | Weight SS (kg/mu00b2) | Reference standard |
|---|---|---|---|---|---|---|
| 20-Mesh | 0.400 | 0.870 | 870 | 46.9 | 1.65 | ISO 9044 |
20 Mesh to Micron & Aperture
| Openings per inch | 20 |
|---|---|
| Aperture (opening width) | 0.87 mm |
| Micron rating | 870 µm |
| Standard wire diameter | 0.4 mm |
| Open area | 46.9 % |
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 20 Mesh
| Option | Wire dia | Aperture | Micron | Open area | Weight (SS) |
|---|---|---|---|---|---|
| Heavy wire | 0.520 mm | 0.750 mm | 750 µm | 34.9 % | 2.78 kg/m² |
| Standard wire | 0.400 mm | 0.870 mm | 870 µm | 46.9 % | 1.65 kg/m² |
| Fine wire | 0.300 mm | 0.970 mm | 970 µm | 58.3 % | 0.93 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 20 Mesh
The standard 20 mesh weave presents an open area of about 46.9%. At this count the mesh presents little flow resistance; selection is normally driven by particle retention and mechanical strength rather than pressure drop.
20 Mesh Cloth Weight
Standard 20 mesh stainless cloth weighs approximately 1.65 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 20 Mesh Plain Weave Wire Mesh
20 mesh plain weave wire 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.
When to Step Up or Down from 20 Mesh
Move to 30 mesh when particles are passing that must be retained; drop back to 10 mesh when the element blinds too quickly or the pressure drop is excessive. In a multi-layer pack, pair this count with a coarser support mesh downstream to carry the pressure load.