Impact Driver

An impact driver delivers rotational force in rapid concussive bursts rather than smooth continuous torque, which is what lets it drive long or stubborn fasteners without stalling the motor or twisting out of your hand the way a drill can under similar load. That same hammering action is also why it's the wrong tool for anything requiring finesse — there's no clutch to limit how hard it drives.

Why it exists alongside a drill

A Drill applies smooth torque with a clutch for control; an impact driver trades that control for raw driving power delivered in bursts, which is dramatically better at sinking long deck screws, lag bolts, or fasteners into dense material without cam-out (the bit slipping out of the screw head under load). Most shops end up owning both — the drill for drilling and controlled driving, the impact driver for anything that needs to go in fast and isn't delicate.

What actually matters

• Quick-release hex chuck — impact drivers use 1/4" hex-shank bits exclusively, and a quick-release collet makes bit swaps fast, which matters given how often this tool gets used specifically for driving many fasteners in a row.
• Torque settings — higher-end models offer multiple power modes, useful for backing off when driving into softer material or smaller fasteners where full impact force risks stripping or overdriving.
• Weight and length — impact drivers are typically more compact than drills of similar power tier, which matters in tight framing or cabinet-interior work.

Where it's the wrong tool

Anything requiring a light touch: driving small screws into thin material, delicate hardware installation, or drilling precise holes (most impact drivers aren't built for standard twist bits the way a drill is, though impact-rated drill bits exist for occasional use). The hammering action that makes it so good at stubborn fasteners is the same reason it will happily strip a screw head or split thin stock if you're not paying attention to torque setting.

Safety

The bursts of torque can twist a workpiece unexpectedly if it's not secured, and bit changes should happen with the tool off — same rule as a drill, doubly true here given how quickly this tool can spin a bit up. Keep a firm grip; the reactive torque from a stalled or bound bit is more abrupt than a drill's.