Stainless Steel Filter Mesh

Last reviewed on October 3, 2026

Filter mesh is fine woven (or sintered) stainless steel wire cloth used to strain particles out of liquids and gases. Unlike paper or felt, a woven stainless screen has openings of a defined geometric size, can be cleaned and reused, and tolerates heat and most process chemicals. This page explains how filter mesh is graded, gives a mesh-to-micron chart for common plain-weave specifications, and covers Dutch weave and sintered mesh for finer or higher-pressure duties.

How Filter Mesh Is Graded

Five numbers describe a woven filter cloth. When you compare quotes, make sure all of them are stated:

• Mesh count – the number of wires (equivalently, openings) per linear inch, e.g. 100 × 100. Rectangular cloths give both directions, e.g. 18 × 16.
• Wire diameter – usually in inches or millimetres. The same mesh count is sold with different wires, so mesh count alone does not fix the opening size.
• Aperture (opening) – the clear gap between adjacent wires. For square plain weave: aperture = 25.4 ÷ mesh − wire diameter (mm), or 1 ÷ mesh − wire diameter (inches).
• Open area – the percentage of the cloth that is open: (aperture ÷ (aperture + wire))² × 100. It drives flow rate and pressure drop.
• Micron rating – for square-weave cloth this is simply the aperture in micrometres (µm). For Dutch weaves and multi-layer media it is a tested nominal or absolute rating published by the manufacturer, because there is no straight-through square opening to measure.

Grade (304, 304L, 316, 316L) and weave type (plain, twill, Dutch) complete the specification. See 304 vs 316 mesh for the material choice.

Filter Mesh Micron Chart (Plain & Twill Square Weave)

The wire diameters below are common market combinations; your supplier may offer heavier or lighter wire for the same count, which changes the micron rating. Apertures are calculated, not measured, and woven cloth has manufacturing tolerances (see ISO 9044 for industrial wire cloth).

For every mesh count from 2 to 635, plus a calculator for your own wire diameter, use the full mesh size chart.

Why some charts say "100 mesh = 150 µm"

Many conversion tables are based on standard test sieves (ASTM E11 / ISO 3310-1), where "No. 100" is defined by a 150 µm aperture and "No. 200" by 75 µm. Industrial filter cloth sold as "100 mesh" is defined by wire count, and with the common 0.0045″ wire its opening is about 140 µm. Both are correct for what they describe — just be clear which one your supplier means.

Choosing a Micron Rating

1. Start from what must be stopped. The aperture should be smaller than the smallest particle that would cause harm downstream — a nozzle orifice, a valve clearance, a pump tolerance. Equipment makers often specify the strainer mesh they want; follow that first.
2. Don't go finer than necessary. Halving the aperture usually reduces open area and makes the screen clog faster. A coarse screen ahead of a fine one (staged filtration) keeps the fine screen working longer.
3. Remember particle shape. A square opening's diagonal is about 1.41 × its side, so long or flat particles can slip through diagonally. For critical duties use a tested rating rather than the geometric aperture.
4. Check flow. Required flow, viscosity and allowable pressure drop set how much screen area you need. Pressure-drop data comes from the filter-housing or strainer manufacturer.
5. Pick the grade for the fluid. 304 suits water, oils and most food duties; 316/316L is preferred where chlorides, brines or acidic products are present.

Dutch Weave Filter Cloth

In a plain Dutch weave, heavier warp wires are spaced apart while finer shute (weft) wires are packed tightly against each other. The result has no straight square openings: liquid follows a tortuous path between wires. Dutch cloths are designated by two counts (for example 24 × 110 or 200 × 1400). They are strong for their fineness and are used for fine liquid filtration, hydraulic and fuel filter elements and polymer screens. Twilled Dutch weaves pack the shute wires even more closely and reach finer ratings.

Because the pores are irregular, Dutch weaves are rated by testing, and published nominal and absolute ratings differ between manufacturers for nominally the same cloth. Always use the rating from the supplier's data sheet rather than a generic chart.

Sintered Mesh

For high-pressure, backwashable or structural filter elements, several layers of woven mesh — typically a fine filter layer protected and supported by coarser layers — are stacked and diffusion-bonded at high temperature in a vacuum or protective atmosphere. The wires bond at their contact points, giving a rigid porous plate that keeps its pore structure under pressure and can be cleaned by backflushing. See the manufacturing process article for more on sintering.

Common Uses

• Water treatment: pre-filters and strainers that protect pumps, meters, UV units and cartridge filters from sand and scale.
• Brewing & beverage: hop and grain strainers, cold-brew filters, juice screens — see the brewing mesh guide.
• Oil & fuel: suction screens and strainers in hydraulic, lubrication and fuel-transfer systems.
• Process & laboratory: sieving powders, protecting instruments and retaining catalysts or media.

Mesh Filter vs Other Filter Media

Woven mesh is a surface filter: particles collect on the face of the screen and can be rinsed or backflushed off. Foam, felt and wound cartridges are depth media that trap particles inside their thickness — they hold more dirt before blocking but are usually replaced rather than cleaned. A common arrangement is a stainless mesh pre-filter protecting a finer disposable cartridge. Our comparison of filtration materials goes into more detail.

Example Specifications

Example filter cloth specifications you can use when requesting quotes (not endorsements of a particular seller):

Related Guides

• Mesh size chart & aperture calculator
• How to measure mesh count and wire diameter
• Woven wire mesh: plain, twill and Dutch weaves
• Industrial applications of wire mesh filters