A tool system is presented. The tool system includes a tool body sized and dimensioned to fit comfortably in a human hand, and includes a plurality of interchangeable tool cartridges. Some of the tool cartridges include a tool bit cover capable of remaining in a closed, locked position sheathing a tool bit. Once installed, the tool bit cover can be unlocked via actuation of a trigger disposed on the body of the tool or on the cartridge. Preferably, the tool bit cover unsheathes the underlying tool bit due to pressure or force of a work surface.