Hacking or side knives may be considered light hatchets or heavyweight knives.
They are a straightforward, straight-edge, resembling a small cleaver.
The back of the blade is exposed for hammering on.
Unusually for an ax, this back edge is meant to be a steel hammer, not a wooden mallet or club.
The handle is a solid steel through tang, with side scales.
The scales are often thick leather, to absorb shocks.
Their typical uses are either for glazier's work, or else as a light froe for splitting timber...