Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by general context]
6. fasteners
7. screws
8. [screws by form]
9. machine screws (fasteners)

Anotations

Scope note:

Machine screws that are permanently combined with a lock washer which was inserted before the thread was cut. The term probably derives from an abbreviation for “assemblies,” because the screw and washer are pre-assembled when purchased.