Filter Screen & Mesh Guide | WireMeshQA

Filter Screen Mesh: Micron Ratings & Uses

Quick answer

Filter screen mesh is woven or sintered wire mesh selected by micron rating to separate particles from liquids and gases, used as filter discs, cartridges and multi-layer elements where a defined, repeatable particle cut-off is required.

By the WireMeshQA editorial team · Independent wire mesh reference

What is filter screen mesh?

Filter screen, or filter mesh, is precision woven wire mesh chosen for a specific particle retention rating rather than a simple aperture. It is fabricated into discs, cylinders, cartridges, cones and pleated elements, and is rated in microns - the size of the smallest particle the mesh reliably retains. For coarser separation by size, see mesh for fencing vs filtration.

Micron rating vs mesh count

Mesh count counts openings per inch, while the micron rating describes the actual opening in micrometres. The two are related but not identical, because wire diameter changes the opening at any given count. The table gives representative square-weave values; finer ratings come from Dutch weave and sintered layers.

Mesh count	Approx. opening (micron)	Approx. opening (mm)
20	850	0.85
40	400	0.40
80	177	0.177
100	149	0.149
200	74	0.074
325	44	0.044

Weave and construction for fine filtration

Square (plain) weave: defined apertures from coarse down to roughly 25 to 40 micron.
Dutch weave (plain & twill): coarse warp with fine, tightly packed weft for ratings down to a few microns with high strength and dirt-holding capacity.
Sintered multi-layer: several mesh layers diffusion-bonded together for a rigid, cleanable, high-strength element with precise, stable micron ratings.
Mesh laminate / disc: a fine filter layer backed by a coarser support layer for strength and flow.

Materials

SS316 / 316L: the default for filtration, with strong corrosion and chemical resistance - see SS304 vs SS316.
SS304: economical for less aggressive fluids and gases.
Brass, bronze and nickel alloys: for specialist chemical, fuel and high-temperature duties.

Where filter screens are used

Filtration of oil, fuel, hydraulic fluid, water and process chemicals.
Filter discs and strainers in pumps, nozzles and inline housings.
Polymer, paint and food processing - melt filters and safety screens.
Gas filtration, venting and flame-arrestor elements.

How to choose and buy filter mesh

Start with the micron rating that retains your smallest target particle, then choose a weave and construction that deliver it with adequate flow and dirt-holding capacity. Pick the alloy for the fluid and temperature, and specify disc diameter, layer build and edge treatment. Convert mesh count to micron with the spec converter and the opening-size guide.

Tip

Specify whether you need a nominal or absolute micron rating - absolute ratings retain particles more reliably and matter for critical hydraulic and process filtration.

Frequently asked questions

How do I convert mesh count to microns?

As a rough guide, 80 mesh is about 177 micron, 100 mesh about 149 micron, 200 mesh about 74 micron and 325 mesh about 44 micron, but the exact opening depends on wire diameter. Use the actual micron rating for filtration rather than mesh count alone, and our spec converter to translate between the two.

What mesh is best for fine liquid filtration?

For fine liquid filtration below about 25 to 40 micron, square weave runs out of resolution, so Dutch weave (plain or twill) or sintered multi-layer mesh is used. Dutch weave gives high strength and dirt-holding capacity, while sintered mesh offers rigid, cleanable elements with precise, stable micron ratings.

What is sintered wire mesh?

Sintered wire mesh is several layers of woven mesh diffusion-bonded together under heat and pressure into a single rigid sheet. It combines a fine filter layer with coarser support layers, giving high strength, a stable micron rating, good flow and the ability to be back-flushed and cleaned, ideal for demanding filtration.

What is the difference between nominal and absolute micron rating?

A nominal rating means the mesh retains most, but not all, particles of that size, while an absolute rating means it retains virtually all particles at or above that size. Absolute-rated filters give more reliable separation and are specified for critical hydraulic, fuel and process filtration where breakthrough must be minimised.

What material should a filter screen be made from?

SS316 or 316L is the usual default for filtration because it resists corrosion and most chemicals, including chlorides. SS304 is economical for less aggressive fluids, while brass, bronze and nickel alloys suit specialist chemical, fuel or high-temperature duties. Match the alloy to the fluid, temperature and any chloride exposure.

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