While screws with a Square/Phillips combination drive can be turned with either a Square or Phillips bit, these make the best contact so you can apply high torque without slipping and stripping the recess. They are also known as Quadrex bits.

Hex shank bits (also known as insert bits) are used in hand drivers or with a bit adapter in power tools.

Hex shank bits for power tools have a groove in the shank and fit directly into power tools without an adapter. They offer more reach for recessed holes and less wobble compared to a hex shank bit used with an adapter.