Why are there such differences in the numbers and words used to identify abrasive grit sizes?
The numbering systems used to identify abrasive grits are designed to meet standards of different countries or are measured with different methods. • Mesh Grades : The most common methods used in the USA are mesh grades, which are screens of mesh that abrasives can fall through. The finer the mesh, the smaller the grit size, so a 120 mesh is coarser than a 180 mesh. • Micron sizing : With this system, the grit is measured in microns (one millionth of a meter), and a 120μ (micron) grit is finer than an 180μ grit. • CAMI: The USA measurements are defined by ” CAMI ” ( Coated Abrasives Manufacturers’ Institute). • FEPA: European abrasives are defined by “FEPA” (Federation of European Producers of Abrasives). With this system, a P with the grit size indicates a coated abrasive while an F indicates a bonded abrasive. • JIS: The Japanese system for measuring abrasives is defined by a “JIS” (Japanese Industrial Standard) document. • Note: Cross references are made by several sources, but do n
