Chamfer finish line is usually indicated in cases of:
Chamfer

It is an obtuse-angled finish line.
It is distinct.
Exhibits least stress.
Most conservative.
Indicated where metal forms the margin of a restoration, e.g. complete metal crown. Should not be given for porcelain restorations as the obtuse angle produces shearing forces which is not well tolerated by porcelain.
It is prepared using a round-end tapering diamond. This is produced by sinking in half the diamond into the tooth. The tip produces the chamfer while the sides give the necessary taper to the axial surface.
All metal restorations
All ceramic restorations
Facial margin of PFM crown
All of the above