This SAE Aerospace Information Report (AIR) discusses the terminology@ types@ method of manufacture and chemistry of the fine wire meshes used for filtration of hydraulic@ lubrication fuel system@ and similar applications. Information contained herein may be used for quality assurance testing to unsure that a high performance filter grade wire mesh is acceptable for use in an aerospace application. This document pertains to meshes as coarse as 4x4 wires/cm (10x10 wires/in) or coarser@ as well as to meshes as fine as 155 x 110 wires/cm (400x2800 wires/in) or finer. Fine wire meshes refer to all wire meshes used in the manufacturing of filters for the aerospace industry. This includes not only the very fine meshes used for filtration@ but also the coarser meshes used as a backup or supporting material.