How to use an impact driver

Loading bits

Impact drivers take 6.35 mm (1/4 inch) hex shank bits. Pull the collet forward on some models, or just push the bit in on others, until it clicks. Use bits marked impact rated or impact ready; standard bits can shatter. See impact driver bits explained.

For drilling small holes, use hex shank drill bits. For sockets, use an impact rated hex to square adapter, as covered in can an impact driver remove wheel nuts.

Choosing a speed or mode

Many impact drivers have two to four speed or power modes, and some add special modes for self drilling screws or to stop once a screw is seated. Use a low mode for small screws, hinges and soft materials, and full power for long screws into joists. See impact driver torque settings explained.

The trigger is variable, so you can drive gently even in a high mode. Start slowly every time.

Driving a screw step by step

This method works for most wood screws and decking screws. Practise on an offcut first so you learn how quickly the tool drives, and how soon you need to ease off the trigger as the head reaches the surface.

1. 1

   Fit the right bit for the screw head, PZ2 for most UK wood screws.

2. 2

   Set a low mode for the first few screws until you get a feel for the tool.

3. 3

   Place the screw on the bit, hold the driver in line with the screw and squeeze gently to start it.

4. 4

   Once the screw bites, increase the trigger and let the impacts start. Do not lean on the tool.

5. 5

   Ease off as the head approaches the surface and stop when it is flush.

6. 6

   For hardwood, near board ends and in thin strips, drill a pilot hole first.

See impact driver kits →

Avoiding stripped heads and snapped screws

Stripped heads usually come from a worn bit, the wrong bit size or the driver tilting off line. Replace bits once the tips are rounded. Snapped screws happen when cheap or thin screws meet hardwood without a pilot hole, or when a powerful driver keeps hammering after the head is seated.

With small screws and soft materials, an impact driver can easily overdrive. If you need fine control, use a drill with the clutch set low instead; see drill clutch and speed settings.

• Use quality bits that fit the head snugly.
• Keep the driver in line with the screw.
• Pilot drill hardwood and near ends.
• Stop as soon as the head is flush.

Drilling and other jobs

You can drill holes in wood and metal with hex shank bits, but there is no chuck and no clutch, so accuracy is lower than a drill. Impact drivers are not for masonry; the blows turn the bit rather than hammer it into the wall. See combi drill vs impact driver.

For bolts and nuts, a hex to square adapter and impact sockets work, within the driver's torque.

Note:Wear eye protection and hearing protection. Impact drivers are loud once impacting. Keep fingers away from the bit and screw tip, and check for hidden cables and pipes before driving into walls and floors.

Looking after the driver

Blow out dust from the vents and collet, keep bits clean and store the driver with the battery removed. If the collet stops locking bits, check the manual; some can be cleaned, others need a service agent.

Keep batteries charged and stored as in storing tool batteries. A small 2 Ah pack keeps the driver light for overhead work, while a 4 Ah or 5 Ah pack suits long decking sessions.

Frequently asked questions

Do you need to push hard on an impact driver? No. Light pressure to keep the bit in the head is enough. The impacts do the work.

Can I use normal screwdriver bits? They may fit, but they can snap. Use impact rated bits.

Can an impact driver drill holes? Yes, with hex shank bits in wood and metal. Not in masonry.

Why does my impact driver keep clicking? That is the impact mechanism working once the screw meets resistance. It is normal.