This page covers the 400 mesh count of twill weave wire mesh: the woven specification per ISO 9044 / ASTM E2016, the particle size it retains, the open area it presents to flow, and the neighbouring counts to step to when the separation requires it.
400 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 |
|---|---|---|---|---|---|---|
| 400-Mesh | 0.036 | 0.028 | 28 | 18.8 | 0.27 | ISO 9044 |
400 Mesh to Micron & Aperture
| Openings per inch | 400 |
|---|---|
| Aperture (opening width) | 0.034 mm |
| Micron rating | 34 µm |
| Standard wire diameter | 0.03 mm |
| Open area | 27.7 % |
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 400 Mesh
| Option | Wire dia | Aperture | Micron | Open area | Weight (SS) |
|---|---|---|---|---|---|
| Heavy wire | 0.039 mm | 0.025 mm | 25 µm | 14.9 % | 0.31 kg/m² |
| Standard wire | 0.030 mm | 0.034 mm | 34 µm | 27.8 % | 0.19 kg/m² |
| Fine wire | 0.023 mm | 0.041 mm | 41 µm | 41.7 % | 0.10 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 400 Mesh
The standard 400 mesh weave presents an open area of about 27.7%. At this fineness, pressure drop rises quickly as cake builds — size the element area generously and plan a cleaning or backwash cycle.
400 Mesh Cloth Weight
Standard 400 mesh stainless cloth weighs approximately 0.27 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 400 Mesh Twill Weave Wire Mesh
400 mesh twill weave wire mesh is commonly specified for micro-filtration of process liquids and gases, catalyst recovery, fine chemical and pharmaceutical processing, and precision laboratory analysis.
Plain, Twill or Dutch Weave at This Rating?
Twill weave passes each weft over and under two warps, which allows a heavier wire at a fine count than plain weave can accommodate. Specify twill when the aperture is fine but the cloth still needs body — typically 200 mesh and finer.
When to Step Up or Down from 400 Mesh
Move to 500 mesh when particles are passing that must be retained; drop back to 325 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.