Top IPC subclasses
1
|
E04C
|
5
|
Structural elements; building materials
|
2
|
E04B
|
5
|
General building constructions; walls, e.g. partitions; roofs; floors; ceilings; insulation or other protection of buildings
|
3
|
B28B
|
1
|
shaping clay or other ceramic compositions, slag or mixtures containing cementitious material, e.g.
|