571449-2

A flat metal or plastic item of various peripheral shapes having a solid (not laminated) cross-section. It is designed to maintain a predetermined distance between two surfaces. For round items without a hole having a solid rectangular cross-section use disk, solid, plain. For round or hexagonal items with only one hole centrally located and with the length (thickness) exceeding 25 percent of the outside diameter or distance across peripheral flats, see spacer, sleeve. The thickness between the two parallel bearing surfaces must be 0.006 inch, (0.152 mm) or more for items less than 1/4 inch (6.35 mm) across the peripheral diameter, or smallest overall outside dimension, or must be 0.016 inch (0.406 mm) or more for items 1/4 inch (6.35 mm) or greater across the peripheral diameter or smallest overall outside dimension. For items with a thickness less than those indicated above, see shim. For items with one hole centrally located conforming to the above dimensional criteria use washer, flat or spacer, ring as applicable. When thickness and/or outside_diameter_or_smallest_overall_outside_dimension_is_designated_as_a_tolerance/dimension_the_maximum_dimension_will_be_used_to_determine_compliance._excludes:gasket;_insulator_(as_modified)_and_mounting_pad,_electrical-electronic_component.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

mil-s-18729 mil spec single material response material document and classification, 28.0 rockwell c minimum and 34.0 rockwell c maximum hardness rating, qq-p-416,type 1,class 2 fed spec single treatment response surface treatment document and classification, steel comp 4130 material, cadmium surface treatment