The slotter machine falls under the category of the reciprocating type of machine tool similar to a shaper to a shaper or a planner. It operates almost on the same principle as that of a shaper.

The major difference between a slotter machine and a shaper machine is that in a slotter the ram holding the tool reciprocates in the vertical axis. whereas in a shaper the ram holding the tool reciprocates in a horizontal axis. A vertical shaper and slotter machines are almost similar to each other as regards their construction, operation, and use.