The confusion is built into the shape: both are pistol-grip, both spin a bit, both come in the same battery kit. So people grab whichever and then fight the tool — a drill that stalls and twists their wrist driving long screws, or an impact driver that overdrives a cabinet screw and strips the head before they can blink. Neither is faulty. You just used the wrong one, because nobody told you they work in fundamentally different ways.
What a drill actually is
A drill (properly a "drill/driver") has two things the impact driver doesn't: a three-jaw chuck that grips any round or hex shank across a range of sizes, and a torque-limiting clutch — the numbered collar behind the chuck. The chuck lets it hold actual drill bits, spade bits, hole saws, and wire-wheel accessories. The clutch lets it stop applying force at a set point so you can sink a screw exactly flush without overdriving it. Its force arrives as a smooth, controllable spin, which is exactly what drilling a round hole needs. (The clutch is the most ignored control on the tool — see the dial you're ignoring.)
What an impact driver actually does
An impact driver has no chuck and no clutch — just a ¼-inch hex collet that snaps bits in and out. Its trick is internal: when it meets resistance, a spring-loaded hammer and anvil inside start striking, delivering many rapid rotational blows per second on top of the spin. It is the cordless equivalent of giving a screwdriver a sharp twist-and-whack at the same time. That hammering does three useful things: it drives long and large fasteners that would stall a drill, it does so without transmitting the reaction torque back into your wrist (the tool absorbs the twist, not you), and it loosens stuck or rusted fasteners a drill can't budge. The price is control — it is loud, it pulses, and it does not know when to stop.
Why an impact driver eats small screws
Because it has no clutch, an impact driver will happily keep hammering after the screw is seated — so on a small brass screw, a cabinet hinge, or anything into thin or soft material, it strips the head, snaps the screw, or buries it through the surface before you react. The same brute force that is a gift on a 3-inch deck screw is a liability on a #6 into a drawer front. For delicate, precise, or repetitive small-fastener work, the drill's clutch is the whole point.
Don't confuse it with a hammer drill
This trips up nearly everyone: a hammer drill is a different tool again. It adds a forward percussive action — punching in and out along the bit's axis — to chip through brick, block, and concrete while drilling. An impact driver's blows are rotational (around the bit), for driving. So: drill = spin; hammer drill = spin + forward punch (masonry holes); impact driver = spin + rotational blows (driving fasteners). Three different jobs.
| Drill / driver | Impact driver | |
|---|---|---|
| Holds bits with | Keyed/keyless 3-jaw chuck (any shank) | ¼-in hex collet (hex bits only) |
| Has a clutch? | Yes — set torque, won't overdrive | No — drives until you release |
| Best at | Drilling holes; precise, delicate, small screws | Long/large screws, lags, stuck fasteners |
| Weakness | Stalls and twists your wrist on big fasteners | Strips/snaps small screws; loud; no finesse |
So which do you buy?
If you buy one tool, buy the drill/driver — it can drill (the impact can't, really, without special hex-shank bits) and it can drive screws with control. It handles the overwhelming majority of home jobs. The impact driver earns its place the day you build a deck, hang a gate, drive structural screws or lags, or assemble a lot of flat-pack — jobs where the drill stalls and your forearm pays for it. That's why they're so often sold as a two-tool combo kit on one battery platform: it's genuinely the right pairing, not just an upsell. Drill in one hand to bore the pilot hole, impact in the other to drive the fastener, no swapping bits.
The short version
A drill spins; an impact driver spins and hammers. The drill drills holes and places small or delicate screws with clutch-controlled precision; the impact driver muscles in long, fat, or stuck fasteners without wrecking your wrist, but has no clutch so it chews up small screws. Own a drill first, add an impact when the work demands it, run impact-rated bits in the impact, and don't mistake either for a masonry hammer drill. Next, understand the battery they share — amp-hours vs voltage — and whether a brushless motor is worth it.
Drills, impact drivers, and combo kits on eBay
For most people the answer is a drill first, or a two-tool combo on one battery; buy impact-rated bits if you get the impact. We earn a small commission on qualifying sales and pass a share to the charity you choose; your price is unchanged. Full disclosure.