Filter Screen Mesh Standards

Mesh count refers to the number of sieve holes within an area of 1 inch × 1 inch (approximately 25.4 mm × 25.4 mm) on a filter screen. For example, a 100-mesh filter screen means there are 100 sieve holes within an area of 1 inch × 1 inch.

A higher mesh count indicates a greater number of sieve holes, with each individual sieve hole being smaller in size; conversely, a lower mesh count means fewer sieve holes, with each hole being larger. There is an approximate conversion relationship between mesh count and aperture size (based on the American standard), as follows:

The mesh count determines the size of particles that the filter screen can intercept. High mesh counts (such as above 200 mesh) can filter out tiny particles and are suitable for scenarios with high requirements for fluid cleanliness (e.g., hydraulic systems, medical injections). Low mesh counts (such as 20 - 40 mesh) are used for coarse filtration to intercept larger impurities (e.g., leaves, sand and gravel).