QUESTION: I’ve just bought my first home, and now I need to buy a drill. I walked into my local hardware shop thinking this was going to be an easy purchase, but when I got there I couldn’t get over the variety. What’s the difference between a cordless drill, a hammer drill, an impact driver and a rotary hammer drill, and which do I need? Thanks!
ANSWER: We remember when a drill was a drill, and when you needed one you walked into the hardware store, chose between two popular brands, paid and walked out. Times have changed!
Firstly, lets look at a cordless drill. These are incredibly useful and versatile tools that we couldn’t do without in our workshop. But they have definite strengths and weaknesses! They use rechargeable batteries (buy the one with the highest voltage you can afford, and preferably with two batteries) so it can be used where electricity isn’t accessible. They’re best suited for working with wood – you can use them for drilling holes or screwing screws into soft materials (wood or aluminium) or thin steel plate.
An impact driver is similar to a cordless drill, but much more powerful. Most of them use a quick-release chuck and only accept hex-shaped bits, so your standard round drill bits won’t fit. Also be sure to use an impact-rated drill bit with an impact driver, as standard ones can sheer under the torque. Like a cordless drill, an impact driver should only be used in softer materials, for screwing screws or drilling holes.
Then there’s the hammer drill. This is the standard 220V drill that your dad probably had in the garage drawer. Most of them can switch between hammer mode and a normal drilling action. The hammer mode means that the drill hits the bit forward constantly while it drills, and is suited to hard materials like bricks, concrete, stone and similar materials.
A hammer drill can be used for metals, woods and softer materials, but in normal drilling mode, not hammer mode. A hammer drill isn’t really suitable for screwing in screws, thanks to the higher speeds and torque than that of cordless options. (Some cordless drills feature a hammer action, which makes them extra versatile around the house.)
Finally, there’s the rotary hammer drill. A rotary hammer drill is basically a hammer drill on steroids that uses a piston to powerfully ‘hammer’ the bit forward. The hammer action is slower but more powerful than a hammer drill, and the rotary hammer is incredibly useful for drilling into hardened cements, especially if you need bigger holes.
That said, a rotary hammer drill is best suited for heavy construction work, and using one around the house is a lot like swinging a sledgehammer to knock in nails.
So what do you need? Personally, I’d go for both a cordless drill and a hammer drill. The first is invaluable around the house for screwing and drilling, but you don’t want to damage it (or get frustrated) by using it for drilling into walls. For that you really should have a hammer drill.
Hope this helps!
David van den Bergh (DIY Professional)