Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. organic material
7. oil (organic material)
8. [oil by form or function]

Anotations

Scope note:

Petroleum products, usually heavy distillates after kerosene, that are classified based on their viscosity for various purposes, ranging from very thin oils for high speed textile machinery, to heavier, tackier, or stickier oils for bearings or open gears. Automobile oil is the most common in the United States.