GMNA GM4252M PDF

1 SCOPE.

These specifications cover basic requirements for plated finishes of the zinc and cadmium types. A system of suffix letters and numerals is provided for designating such details as: Plate thickness Conventional vs mechanical (peen) plating Plate plus chromate treatment Bright plate plus clear chromate Black plate Plate plus chromate plus color dye Neutral salt spray test resistance Example: GM4342M Code 20D24 indicates a zinc plated finish, 0.0002 inch minimum thickness, chromate treated to withstand 24 h neutral salt spray test without evidence of white corrosion products.