Impact screwdriver set, ideal for stubbornly stuck screws and bolts. This impact screwdriver is a handy tool for loosening screws and bolts that are very tight. It should be hit with a hammer. The resulting downward movement is converted into a strong lateral force in the impact screwdriver. With this force, the screw is moved. The screw startles off, as it were. Due to the downforce, there is less chance of "madnessing" of the screw or bolt.