How we test drills
By Aaron West
We’ve put a wide range of cordless drills to the test, pitting each against stone, wood, metal and concrete to see which can tackle the toughest tasks.
Our test lab results reveal the models that will drill quickly, drive screws efficiently, and last all day. Plus, our expert panel assess how easy they are to handle and use.
We've tested cordless drills from brands including Black & Decker, Bosch, Makita, Stanley and Worx. Our reviews answer the most important questions you should consider when buying a drill:
- How quickly does it drill holes?
- Does it work well as a screwdriver?
- How good are the battery and charger?
- Is it easy to use?
- Will it last?
- Should I buy it?
The difference between a cordless drill which excels at our tests and one which struggles can be startling. Check out all of our drill reviews to make sure you spend your money wisely and avoid a dud.
Most of the emphasis in our cordless drill tests is based on their two main functions: drilling and driving screws. We also measure how well each drill keeps its charge, as there's no use having a powerful drill that runs out of battery before you've finished the task.
Over the course of our testing, we drill into sandstone, wood and metal, using a range of drill bit diameters, to simulate all the conditions you’re likely to face in your everyday tasks.
For combination drills, we also pit them against concrete, to see how well their hammer action handles the toughest DIY jobs. This score is then incorporated into the overall performance score.
For each screwdriver test, we drive a variety of sizes of screw into both wood and metal. This is to test how easily the cordless drill will be able to tackle common DIY tasks, from constructing fiddly flat-pack furniture, to larger construction jobs.
We test drills to see if they can screw slowly (for the best control) and effectively. We test each drill on each of its torque settings, and screws of different sizes, to determine whether it has adequate torque control for a wide variety of jobs.
To test how long each battery lasts, we measure how many holes it can drill and screws it can drive on a full charge. A good cordless drill will be able to drill hundreds of holes before losing power - enough for a full day's work.
We also test each drill to see how many holes it can drill after a quick 15-minute charge. This can be handy if you need to do a small task in an emergency, and we find that some models are much better at this than others.
To assess the convenience of a drill, we ask an expert panel to rate how easy and comfortable the drill is to use overall, filling out a questionnaire with their thoughts on each drill's specific qualities.
Putting these together, we can evaluate how convenient the drill is to use.
To test whether the drill will remain fast and effective after years of work, we run the drill for 33 hours, turning it on and off repeatedly, to simulate years of actual use. If the drill lasts the full duration, it passes the endurance test - some break down completely, while others develop faults along the way.
We test whether the spin speed decreases over the test, and inspect each drill for defects - a reduction in speed or a defect at the end will result in a lower endurance score.
We also safety-test each drill for a variety of different possible issues, including electrical safety and electrical continuity. For example, we test each drill for what would happen should you accidentally drill into a live electrical cable. Any drill that raises a safety concern has its overall test score limited and can't become a Best Buy.
We combine all the scores from the tests listed above to come up with an overall rating for each drill.
The full drill test score is made up of:
- 55% Performance (of which 36% drilling, 36% screwdriving, 21% battery, and 7% hammer-action for combination drills)
- 25% Convenience
- 10% Features (length of charging time; whether the drill comes with bit storage and two batteries)
- 5% Instructions
- 5% Endurance, with a limiter for low-scoring drills.
Drills need to score 68% overall in our tests to be a Best Buy. We think that any drill that scores less than 45% is best avoided, so we highlight it as a Don't Buy.
Make sure you avoid a dud and choose a drill that excels in our tests - check out our Best Buy drill reviews.