In this video, This Old House contributor Mark Clement explains the difference between a cordless drill/driver and an impact driver. Unlike the wide versatility of a cordless drill—which is primarily used to fasten or tighten in nuts, bolts and screws—an impact driver contains a different mechanism to drive the bit, so it can only use bits with a hex shank.
Built to work on large fasteners, an impact driver is both more compact and delivers more torque, but those advantages come at a cost: It's more expensive and considerably louder than a drill/driver.
Learn how to:
- Differentiate between a cordless drill/driver and an impact driver.
- Understand the bit-driving mechanism.
- Evaluate whether an impact driver is right for your project.