Magnetising a screwdriver. Magnetic device (green) being used to magnetise a screwdriver. The inset picture (blue circle, lower right) shows a screw magnetically held in place at the end of the screwdriver. This makes it easier to handle the screws, making it less likely that screws will be dropped or lost. The device can also be used to demagnetise the screwdriver. Magnetism is a stronger force than gravity, and a relatively small magnetic field can overcome the weight of the screws and prevent them falling to the ground.