Desiccant Mesh Sizing

What Is "Mesh"?

Sieve with mesh for desiccant sizing

The US mesh size system is a standardization of granule particle sizes in powder/pellet materials, including bulk desiccants like silica gel and molecular sieve. The Mesh size is based on the number of openings in a linear inch of a wire mesh sieve; the number of openings is inversely proportional to the size of the openings. For example, a mesh with 4 openings per inch will allow much larger particles to pass through than a mesh with 100 openings in an inch.

Bulk desiccant listings will often include particle sizes in millimeters, microns, and/or inches along with a mesh size. The mesh size corresponds to the largest desiccant bead diameter for that product. For instance, 4 mesh indicates particles that are 4.76 mm or smaller, and 100 mesh corresponds to particles that are 0.149 mm or smaller. See the accompanying table for a range of common U.S. mesh sizes and corresponding particle sizes.

Desiccants are also listed as falling within a range of mesh sizes, usually expressed as “8x12 mesh” or “8-12 mesh,” for example. This indicates that the desiccant beads fit through the first mesh size, but not the second. An 8x12 mesh desiccant will therefore include beads that are approximately 1.7 to 2.3 mm in diameter. See the table at the bottom of this page for an extensive list of U.S. mesh sizes.