An impact driver is a manual tool that delivers a strong, sudden rotational and downward force, often used by mechanics to loosen larger screws (bolts) and nuts that are corrosively "frozen" or over-torqued.
An impact driver is a manual tool (bolts) and nuts. These nuts are corrosively "frozen" or over-torqued. This manual tool delivers a strong, sudden rotational and downward force. Downward force is often used by mechanics. This was to loosen larger screws.