Mesh (scale)

Mesh is a measurement of particle size often used in determining the particle-size distribution of a granular material. For example, a sample from a truckload of peanuts may be placed atop a mesh with 5 mm openings. When the mesh is shaken, small broken pieces and dust pass through the mesh while whole peanuts are retained on the mesh. A commercial peanut buyer might use a test like this to determine if a batch of peanuts has too many broken pieces. This type of test is common in some industries, and, to facilitate uniform testing methods, several standardized mesh series have been established. Metal surfaces mechanically polished are designated as having a mechanical finish related to the abrasive used. Many mesh sizes were historically given in the number of holes per inch; due to the width of the wires in the mesh, mesh numbers did not correspond directly to fractional inch sizes, and several different systems standardized with slightly different mesh sizes for the same mesh numbers.