Why impact drivers exist
If you have only used a drill, impact drivers can feel confusing. They are smaller than many drills but can drive long screws and lag bolts that make a regular drill stall or burn out. Understanding what is happening inside the tool makes it much easier to choose the right one for your work.
How an impact driver works
Rotational impacts instead of constant torque
A drill applies smooth, continuous torque. When it reaches its limit, the motor simply struggles and can twist your wrist. An impact driver uses a hammer and anvil style mechanism that repeatedly "hits" the bit around in rotation. Those short bursts of torque let the driver keep turning fasteners even when resistance is high while transferring less shock back into your hand.
Hex collet and driver bits
Impact drivers use a 1/4 inch hex collet instead of a chuck. Bits snap in and out quickly, which makes them ideal for driving lots of screws or switching between sizes. This also means you do not use standard drill bits directly unless they are impact rated with a hex shank.
Impact driver vs drill: key differences
Best jobs for a drill
A drill is your go to tool for:
- Drilling clean holes in wood, metal, or plastic with twist bits.
- Boring larger holes with spade or Forstner bits.
- Light duty screw driving where control matters more than speed.
Drills give you fine control over speed and clutch settings, which is helpful for delicate tasks like assembling cabinets or working with soft materials.
Best jobs for an impact driver
An impact driver shines when you need to:
- Drive long deck screws, structural screws, or lag bolts.
- Work overhead or all day without fighting torque twist.
- Remove stubborn fasteners that a drill cannot break loose.
For framing, decking, outdoor structures, and many remodeling tasks, an impact driver simply works faster and is easier on your wrists.
When you should own both
For many DIYers the best setup is a drill and impact combo kit that shares batteries. The drill handles precise drilling and light fastening. The impact driver takes over for heavy driving and repetitive screw work. Because both tools often share a charger and batteries, combo kits can be better value than buying either tool alone.
Where to go next
Once you understand what each tool is best at, the next step is choosing specific models.
- Use our detailed DeWalt 20V MAX drill and impact driver review to see how a popular combo performs under load.
- Read our DeWalt vs Milwaukee hammer drill comparison when you are deciding which ecosystem to invest in for the long term.
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