Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Measuring Devices (hierarchy name)
5. measuring devices (instruments)
6. [measuring devices for extent]
7. distance measuring devices
8. size measuring devices

Additional parents:

1. top of the aat hierarchies
2. Objects Facet
3. Object Genres
4. object genres
5. object genres by form
6. blocks

Anotations

Scope note:

Hardened steel blocks having two flat, parallel surfaces with the parallel distance between the surfaces marked to a guaranteed accuracy of a few millionths of an inch; used in manufacturing processes as a precise measuring standard.