The Use Principle of Screwdriver

The screwdriver is a tool that is used to twist the screw to force it in place, usually with a thin wedge, with a minus sign and a positive sign. There is a common hex screwdriver, including hexagonal screwdriver.
The screwdriver is used to pry the paint cover, which used the working principle of the lever. The greater the distance from the power point to the fulcrum more effort, so long screwdriver is more effort than the short screwdriver.
When the screwdriver is used to screw the screw, it use the axle of the working principle. When the wheel is bigger and more labor-intensive, so the use of coarse screwdriver is more effort than the use of fine screwdriver.