Strainer Mesh-to-Micron Conversion Chart

Strainer and filter screens are specified two ways — by mesh number (wires per inch) or by micron (opening size). This chart converts between them so you can match a screen to the particle size you need to stop.

Conversion chart (US mesh)

Nominal openings. Actual opening varies with wire diameter, so treat these as standard references.

How to read it

Higher mesh number = more wires per inch = smaller openings = finer filtration. A 20-mesh screen stops particles down to ~840 microns; a 100-mesh screen stops down to ~149 microns. Finer screens protect tighter equipment but clog faster and add pressure drop.

Picking a screen

Start with the smallest orifice or clearance you're protecting downstream (a spray nozzle, pump, or meter), then choose a mesh that stops particles below that size. For general pipe-debris protection, perforated or coarse mesh (20 mesh) is usually enough. See the Y-strainer selection & sizing guide for the full picture.

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Frequently Asked Questions

What is the difference between mesh and microns?

Mesh is a count of wires per linear inch in a woven screen — it describes the screen's construction. Microns measure the actual opening size between wires. The two are related but not the same: a higher mesh number means smaller openings and a finer micron rating, but the exact micron value also depends on the wire diameter used in weaving.

Does a higher mesh number mean finer filtration?

Yes. A higher mesh number means more wires per inch, which leaves smaller gaps between them. A 20-mesh screen passes particles up to roughly 840 microns, while a 100-mesh screen stops particles down to about 149 microns. The trade-off is that finer screens add more pressure drop and clog faster in dirty service.

What mesh strainer do I need to protect a pump or spray nozzle?

Start by identifying the smallest clearance in the equipment you are protecting — the pump impeller clearance, nozzle orifice, or meter passage. Choose a mesh rating fine enough to stop particles below that size. For general pump-inlet protection against pipe scale and debris, a 20-mesh (840-micron) screen is usually sufficient. For precision nozzles or meters, 100-mesh or finer may be required.

What is the difference between a perforated screen and a mesh screen?

A perforated screen is a sheet of material with punched or drilled holes, typically used for coarse filtration of large debris where maximum flow area matters. A woven mesh screen uses interlaced wires to achieve much finer, more consistent openings at the cost of a smaller open area. Perforated screens are common in basket and pump-inlet strainers; woven mesh inserts are used when tighter particle control is needed.

Can I convert microns directly to inches?

Yes — one micron equals 0.000039 inch, or conversely one inch equals 25,400 microns. The chart on this page provides pre-calculated inch equivalents for common mesh sizes so you can cross-reference with equipment specs listed in decimal-inch dimensions.

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