Special Features:

4-40 unc-2b inside threaded, finish plated all over with copper mil-c-14550a class 3, then tin plated mil-t-10727b type 1

Properties:

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.