This Standard covers general and dimensional data pertinent to the various types of screw and captive washer assemblies, otherwise known as SEMS. SEMS products may include screws, tapping screws, or bolts in sizes #0 through ½" diameters in various grades and materials. The word SEMS is recognized in the United States as a generic term applicable to screw and washer assemblies. Also included in this Standard are appendices to illustrate the relative proportions of plain and conical washer SEMS.