Rectangular cross-sectional shape style, 2.8120 inches minimum and 2.8130 inches maximum outside diameter, round center hole shape style, 1.6240 inches minimum and 1.6250 inches maximum diameter, 0.0605 inches minimum and 0.0645 inches maximum overall thickness, square all corners corner shape

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.