Bearings

The NATO Supply Group (historically known as Federal Supply Group) 31 for Bearings groups together the NATO Stock Numbers (historically known as National Stock Numbers) for mounted bearings, plain un-mounted bearings and anti-friction un-mounted bearings. Typical bearing types include ball bearings, roller bearings, bearing sleeves, thrust bearings, pillow-block bearings and rod-end bearings. NSNs for bearings are extensive with over 500,000 distinct physical types codified by NATO. The NSNs are distinguished by their physical characteristics such as size, material, tapered, parallel, slide, sleeve, roller and ball. In addition to the physical characteristics, quality standards can determine the difference between NSNs, bearings can be commercial grade, marine standard, national aerospace standard (NAS Bearings), Military Standard (MS Bearings), Aerospace Standard (AS Bearings), International Organization for Standardization (ISO Bearings) and American National Standards Institute (ANSI Bearings) to name but a few.