Example of excavator are all except:
Hoe
Ordinary hatchet
Enamel hatchet
Angle former
The four subdivisions of excavators are

Ordinary hatchets
Hoes
Angle formers
Spoons

Chisels are intended primarily for cutting enamel and may be grouped as

Straight, slightly curved, or bin-angle
Enamel hatchets
Gingival margin trimmers

Sturdevants operative dentistry 7th edition page e4