ASME B18.13-2017 (R2022)

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 No. 0 through 1/2 in. 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 is
Nonmandatory Appendix A illustrating the relative
proportions of plain and conical washer SEMS.