Which Wire Mesh Should You Use for Filtration?
Filtration is where mesh selection gets picky. A cloth that works fine as a guard panel can pass the particles you needed to catch, blind off in a week, or corrode out against the wrong fluid. Figures here are nominal and for guidance only, so confirm any grade against your own fluid, pressure, temperature, and your engineer's requirements before you specify.
Mesh Count, Actual Opening, and Micron Are Three Different Numbers
Mesh count is the number of openings per linear inch, measured center to center on the wires. By itself it tells you how many holes sit in that inch; wire diameter decides how big they are.
A 100 x 100 mesh in .0045" wire opens to roughly .0055", about 140 microns. The same count in .004" wire opens to .006", about 152 microns. In .0011" wire the opening runs near .0089", roughly 226 microns. Same "100 mesh" on the purchase order, three meaningfully different cloths.
A filtration spec needs three numbers: mesh count, wire diameter, and nominal opening in inches or microns. For a square weave, given any two the third falls out of the math. Dutch weaves need a published or tested opening, since there is no straight-through hole to calculate. Our guide to mesh count, opening size, and microns walks through it, and the mesh-to-micron conversion chart translates between them.
One caution: the opening is geometry. Retention in service also depends on particle shape, solids loading, cake buildup, and differential pressure.
Weave Type Changes What the Cloth Can Do
Square (Plain) Weave
Equal warp and shute wires, one over one, with straight-through square openings. Flow is high, the geometry is easy to calculate, and it cleans well. Weaving limits put the routine fine end around 400 x 400 mesh, with 500 mesh available in limited alloys and widths, so ask.
Twilled Weave
Each wire passes over two and under two. That flexibility lets a mill pack in a higher count or run heavier wire at a given count, so twilled cloth gets finer and stronger than plain weave, at some cost in flow.
Plain Dutch Weave
Heavier warp wires with much finer shute wires driven tight together. There is no straight-through hole; the openings are the triangular gaps between wires. It typically filters finer than a square weave of comparable wire size and is generally stronger, though flow drops and particles can wedge in the crossings.
Twilled Dutch Weave
The finest of the common woven grades: the twill pattern with tightly packed shute wires, effectively a double layer. As a rule of thumb these reach into the single-digit micron range, and they tolerate higher differential pressure than open square weaves. The actual limit depends on your alloy, span, support, and temperature, so size the element against those, not the weave alone.
The finer grades in all of these families are grouped in the filter grade wire cloth collection.
| Weave | Strength | Relative flow | Cleanability |
|---|---|---|---|
| Plain square | Low to moderate | Highest | Easiest |
| Twilled | Moderate | High | Good |
| Plain Dutch | High | Lower | Moderate |
| Twilled Dutch | Highest | Lowest | Hardest |
Wire Diameter Drives Open Area
For a square weave, open area is the opening divided by the pitch, squared, as a percent. Pitch is fixed by the mesh count, so every thousandth you add to the wire comes out of the hole, and the loss compounds because that term is squared.
Heavier wire buys strength, abrasion resistance, and pressure capability. It can reduce, though not always eliminate, the need for a support screen, so confirm span and pressure with your element design before you drop the backing mesh. Lighter wire buys open area and lower pressure drop. Decide which your process needs before you lock a spec.
The Alloy Has to Survive the Fluid
Opening size does not matter if the cloth dissolves. Type 304 stainless is the general-purpose starting point for water, air, and mild chemical service, and the usual starting point in food and beverage work, though food-contact compliance depends on your application, finish, and sanitation requirements; confirm those against the governing standard. Types 316 and 316L add molybdenum, which improves resistance to chlorides, brine, seawater, and many acids, and 316L is the common pick for welded assemblies. Our comparison of 304 vs. 316 stainless wire mesh shows where the extra cost pays for itself.
Brass, copper, and bronze still show up for conductivity, non-sparking requirements, and some fuel and oil work. They corrode fast around ammonia. Where a non-sparking material is specified, verify it against your own hazardous-area classification and the governing standard; we supply the alloy, not a hazardous-location certification. Monel, nickel, Alloy 20, and titanium each have a niche in aggressive chemical service, at higher cost and longer lead time. Galvanized and plain carbon steel rust out in wet filtration, and the zinc ends up in your fluid. Check the material guide, then confirm corrosion data for your concentration and operating temperature.
Surface vs. Depth Filtration
A single layer of woven cloth is a surface filter. Particles collect on the upstream face and build a cake. That cake tightens the effective cut, so efficiency climbs while pressure drop climbs with it. You clean or replace on a schedule.
Depth filtration captures particles through the thickness of the media. In wire mesh that means multi-layer packs or sintered laminates, several mesh layers bonded into a rigid sheet. They hold more dirt and resist deformation better, though they cost more and take longer to source. Worth pricing if your element blinds off faster than you can service it.
Six Things That Set the Spec
- Particle size and shape. Spheres, flakes, and fibers behave differently in the same opening.
- Catch or pass. Equipment protection and product recovery sit on opposite sides of the cut.
- Flow and allowable pressure drop. These set your minimum open area and filter area.
- Temperature, pressure, and cycling. Pulsing service favors heavier wire or a laminate.
- Cleaning method. Backflush, ultrasonic, or single-use disposal point to different weaves.
- Part form. Discs, baskets, cylinders, and panels carry their own edge and support needs.
If you have a micron target and no cloth in mind, the Mesh Finder works back to available specs.
Common Mistakes
- Specifying a mesh count with no wire diameter, then getting cloth unlike the last order.
- Chasing fineness without checking open area, then fighting pressure drop and early blinding.
- Picking an alloy on price when the fluid decides how long it lasts.
- Running fine cloth across a large unsupported span with no backing mesh.
Frequently Asked Questions
Is 100 mesh the same as 100 micron?
No, and the gap is wide. A 100 mesh cloth can open anywhere from about 140 microns in heavy .0045" wire to over 220 microns in light .0011" wire, which is exactly why the wire diameter has to be on the order. A 100 micron opening lands closer to 150 mesh, about .0041" or 103 microns on our conversion chart.
How fine can woven wire cloth go?
Square weaves taper off past 400 mesh, though 500 mesh square weave is available in limited alloys and widths. Finer than that, Dutch and twilled Dutch weaves take over. The trade is open area: as the cut gets finer, you need more filter area for the same flow at the same pressure drop.
Can Dutch weave be backflushed?
Sometimes, but not as easily as a straight-through square weave, since there is no direct path for reverse flow and particles can lodge in the crossings. If regular backflushing is central to your process, start from a square weave or a sintered laminate.
Howard Wire Cloth cuts mesh to size from stock in Hayward, California, and has since 1938. Send your opening, flow, and fluid details with a quote request, or ask for samples and bench test a couple of grades first.