Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by origin]
6. biological material
7. plant material
8. [wood and wood by product]
9. [wood by product]
10. lumber
11. [lumber by quality]

Anotations

Scope note:

Lumber that is intended for use in building where allowable properties are required. The grading of structural lumber is based on the strength or stiffness of the piece as related to anticipated uses, such as lumber that is 5 inches or more in both thickness and width.