An item of any peripheral shape usually having one flat or spherical surface and a centrally located hole. It is designed for applications involving moving (kinetic) loads. Except for items fabricated from bearing quality synthetic (plastic) or composed of multilayer material, one bearing surface must either have a specific surface finish designation of 32 microinch (0.8 micrometre) or less, arithmetical average (aa) (arithmetic mean deviation) or one of the following conditions: be lapped or ground; have visible or detectable means of lubrication; grooves, indentations; or self-lubrication. The thickness must not exceed 25 percent of the outside diameter of the shortest distance between peripheral flats (when thickness and/or outside diameter is designated as a tolerance dimension, the maximum dimension will be used to determine compliance). Excludes straight, tubular (without flange) items having a bearing surface(s) parallel to the axis of the bore only. See also washer, flat and spacer, sleeve.
Dept. of the Army 
Dept. of the Air Force 
Dept. of the Navy 
Portugal Classification: Thrust ball bearings
NSN 5990-01-582-1977
NSN 6105-01-520-5889
NSN 5835-01-273-3916
NSN 6650-01-163-6330
NSN 6150-01-389-1978
NSN 5990-01-517-7848
NSN 6130-01-546-8260
NSN 5895-01-274-9294
NSN 5915-01-079-9014
NSN 5855-00-933-9978
NSN 4140-01-097-0136
NSN 5895-01-250-2422