If you have the remotest interest in DIY, then the chances are that you’ll have a cordless drill in your possession. These versatile gadgets allow you to create quick holes in a whole slew of different materials – and these holes can even be threaded in order to receive a screw. What’s more, the drill can then be used to drive the screws themselves.
Given all of this, you might wonder why a more specialised drill would ever be called for. There’s one item that stands out in this category: the impact driver. But exactly why would you want to consider one of these devices, when you already have your trusty cordless drill to hand? Let’s take a look at a few of the key differences.
What distinguishes an impact driver?
Impact drivers provide far higher levels of torque. They’re built for tightening nuts and driving screws, and they typically have a different chuck to a standard drill – they’re made to accept quarter-inch hex shanks. If you’ve ever picked up a screwdriver kit, then you might have noticed a range of screwdriver bits coming in this format. Since the chuck is shaped precisely to receive these, there’s far less loss of power, and less likelihood that the bit will come loose and fly across the room.
Impact drivers tend to be far smaller than their cordless-drill counterparts, and thus can be more easily stowed in crowded toolboxes and workspaces. The compact size also makes it easier to access those screws which would otherwise have been difficult to reach.
The relatively small size of an impact driver is largely down to the fact that it lacks a clutch. You won’t be selecting a level of torque, which makes the driver unsuitable for most everyday tasks. This is a specialised piece of kit – not one that’s designed to replace your existing drill.
How does an impact driver work?
Impact drivers deliver something called rotational torque. You can think of this as akin to the hammer action of a hammer drill. In that instance, the torque comes from behind, helping to push the drill bit back and forth through a tough material like concrete. Your impact driver works along the same principle, except it will twist the driver. Since you’re going back and forth repeatedly, in tiny increments, this won’t cause the device to slip out of the grooves in the fastener – and thus it’ll protect your screws as well as your sanity.
One by-product of this action is volume – since there’s so much back and forth action, you’ll get a considerable amount of volume. Thus, if you’re going to be using one of these tools for an extended period of time, you’ll want to also invest in ear protectors.
Do I need both?
As we’ve mentioned, an impact driver isn’t built to replace a traditional cordless drill, but to do something entirely different. In many cases, a delicate touch is called for, and your impact driver might well be overkill. But if you’re going to be driving lots of screws, then an impact driver makes sense. They’re often to be found in particular industrial and manufacturing contexts – but you can get them in the home, too.
If you’re still confused about what device you need for your job, then be sure to check out SGS Engineering’s comprehensive guide to the subject.