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How to use an impact driver

Updated: 22 October 2026

The bit has snapped, or the screw head has vanished into the timber, and the tool was only meant to fix a gate or a cabinet. How to use an impact driver comes down to the collet, an impact-rated bit that matches the recess, and a trigger you ease off before the head seats. This is the first session with a 1/4 inch hex driver. Model picks stay on the [cordless impact driver comparison](/hub/tools/cordless-impact-driver). Exterior boards are on the [impact driver for decking](/hub/tools/cordless-impact-driver/sub/cordless-impact-driver-for-decking) page. Products Compared did not lab-test a technique. A qualifying purchase can earn a commission at no extra cost to you.

The bit has snapped, or the screw head has vanished into the timber, and the tool was only meant to fix a gate or a cabinet.

Our top picks

DeWalt DeWalt DCF887N

Best overall

DeWalt DeWalt DCF887N
9.4/10about £59.95
View offer
DeWalt DeWalt DCF850N

Alternative

DeWalt DeWalt DCF850N
9.4/10about £98.43
View offer
GALAX PRO GALAX PRO 95307

Best value

GALAX PRO GALAX PRO 95307
8.8/10about £42.83
View offer
On this page
  1. 1.Fit a 1/4 inch hex bit
  2. 2.Use an impact-rated bit, and match the recess
  3. 3.Trigger, then mode
  4. 4.When this tool is the wrong next step

Fit a 1/4 inch hex bit

The nose is a 6.35 mm hex collet, not a jaw chuck and not a square anvil. Pull the sleeve back, push a 1/4 inch hex bit fully home, and release the sleeve. Tug the bit. If it drops out, it was not seated. A round-shank twist bit and an SDS shank do not lock in this nose. Wear eye protection while you drive. A snapped tip leaves the collet at speed. One Dong Cheng review found the bit-lock instructions confusing, so learn the sleeve on a scrap. A magnetic holder still needs a hex shank.

Use an impact-rated bit, and match the recess

Ordinary bits snap because the blows have nowhere to go. An impact-rated bit has a torsion zone that flexes. DeWalt’s DCF887 manual tells you to use impact accessories and to inspect them for cracks. That line belongs to that manual. The non-impact bit fails first on the other drivers here too. Pozidriv has extra ribs between the cross. Phillips does not. Mix them and the bit cams out. Torx stays engaged when the screw offers a star. One DCF850 review says cheap bits shear. That is an anecdote. Retire a chipped tip.
DeWalt DeWalt DCF887N

Testsieger

DeWalt DeWalt DCF887N
9.4/10about £59.95
View offer

Trigger, then mode

Stand the screw before you ask for blows. Set the bit in the recess, hold the driver in line, and squeeze until the thread has bitten. Ease off as the head nears the surface. The blows continue for a moment after you lift, and that moment is how heads disappear. Start on the lowest mode the tool actually has. GALAX PRO has only 0–2800 rpm on the trigger, so there is no mode switch. There is no clutch. On a long run, wear hearing protection. The DCF887 manual declares 96 dB(A) and 22.0 m/s², and the DCF850 manual declares 88 dB(A) and 18.5 m/s², for those models only.

When this tool is the wrong next step

Stop when the job is no longer a hex screw in timber or sheet. Masonry needs a hammer drill. Fine hinge screws are a poor match for a clutchless tool. Wheel nuts are a wrench job, then a torque wrench, which is the split on impact driver vs impact wrench. Stop if the pack is swollen, hot, or split. Specified structural fixings, and work at height, are a professional’s job. The best cordless impact driver page comes after the technique is clear.

Common questions

How do I load a bit?
Pull the sleeve on the 6.35 mm hex collet, push a 1/4 inch hex bit fully in, and let the sleeve close. Tug the bit. If it falls out, seat it again. Round-shank drills and SDS bits do not lock in this nose. Learn the action on a bench, and keep eye protection on once the bit is under load.
Why do my bits snap after a few screws?
The blows are breaking a bit made for a hand driver or a clutched drill. Use a bit marked for impact, with a torsion zone, and retire a chipped tip. DeWalt’s DCF887 manual limits that model to impact accessories. A cheap bit shearing, as one DCF850 reviewer described, is the same failure. Matching Phillips, Pozidriv, or Torx matters as much as the steel, because a cam-out loads the tip sideways.
What is the difference between Pozidriv and Phillips?
Pozidriv has small ribs between the main cross. Phillips does not. The heads look alike in a poor light, and the wrong bit rides out and chews the recess. Match the mark on the packet. If it says PZ2, a PH2 bit is the wrong choice even when it seems to fit for the first two turns. Torx is the recess that resists that ride-out when the screw offers a star.
How hard should I push?
Hard enough to keep the bit in the recess, and no harder. Push along the screw, not at an angle, and let the thread pull the screw in once it has bitten. Extra bodyweight makes the bit walk and snaps tips. Ease the trigger as the head meets the surface. There is no clutch to catch an over-drive, so your finger is the stop.
Which mode do I start on?
The lowest range the tool actually has, until the screw is standing. You can move up if the screw is long and the timber is willing. GALAX PRO has no mode switch, only a trigger from 0 to 2800 rpm, so you start with a short squeeze. Do not begin on the highest range to get it over with. That is how heads strip and how bits leave the collet.

Related pages

Cordless impact driver buying guide

Cordless impact driver

Best cordless impact driver UK by the packs you own

Impact driver for decking boards: ease the trigger

Impact driver vs impact wrench: screws or wheel nuts

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the six amazon.co.uk listings captured on 19 October 2026. HSE vibration and noise duties apply at work. They are not a certificate that a cordless driver is quiet, and they do not set a home DIY dose.

  1. HSE, vibration duties (retrieved 19 October 2026)
  2. HSE, noise duties (retrieved 19 October 2026)
  3. HSE RR1182, battery tools (retrieved 19 October 2026)
  4. GOV.UK, Supply of Machinery (Safety) Regulations 2008 (retrieved 19 October 2026)
  5. GOV.UK, UKCA and CE marking (retrieved 19 October 2026)
  6. DeWalt UK, DCF887 (retrieved 19 October 2026)
  7. DCF887 manual (retrieved 19 October 2026)
  8. BuildWiz, impact driver (retrieved 19 October 2026)