0.450 inches minimum and 0.455 inches maximum overall length, 0.110 inches minimum and 0.115 inches maximum first left step width, aluminum alloy 7075 material, qq-a-225/9,alloy 7085,t7351 fed spec single material response material document and classification, stepped spacer style designator

A tubular shaped item with a round or hexagon peripheral shape having two flat bearing surfaces perpendicular to the axis of the centrally located hole. It is designed to maintain a predetermined distance between assembled parts. The item may be with or without flange(s) of any peripheral shape. The length must exceed 25 percent of the outside diameter or distance across peripheral flats. (when the length, outside diameter, and/or distance across peripheral flats are designated as a tolerance, the maximum dimension will be used to determine compliance.) it must have one or more internal steps (counterbores) and/or external steps on either or both bearing surfaces. Excludes:spacer, optical element. See also washer, recessed and washer, shouldered and recessed.