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. [joints and joint components]
7. joints (connections)
8. [joints by material joined]
9. metal joints
10. metal seams

Anotations

Scope note:

Sheet metal seams comprising one sheet turned and placed over the bent edge of the second sheet. To prevent the elbow from breaking at the joint through handling, the elbow seam is closed using a special machine or with a mallet over a bench stake.