Impact drivers are one of the most useful tools to be developed in the past 100 years, but they aren’t perfect for every job. Sometimes a regular old drill/driver is the better choice, and other times you’re better off reaching for a handheld screwdriver – like when you need to complete delicate work.
Impact drivers are incredibly useful tools when it comes to driving screws – offering powerful rotational bursts that can drive through tough, thick materials with relative ease. As they don’t have variable speed settings, they create a large amount of torque, which means impact drivers can actually be too powerful for situations requiring a soft touch.
I’ll break down some of the common situations where reaching for an impact driver can get you in trouble – and provide some superior alternatives for getting the job done.
When Not to Use an Impact Driver?
An impact driver is ideal when you need to drive large screws and fasteners into a variety of materials without the need for pre-drilling. In fact, most impact drivers can even drive large lag bolts and screws into pressure-treated wood without pre-drilling pilot holes – a task that would be impossible with a standard drill.
Impact drivers are a relatively new tool when compared to the standard cordless drill, and have really taken off with the advancements in lithium-ion batteries.
That said, many of us who grew up using cordless drills/drivers for all of our drilling and driving needs suddenly found ourselves with a tool that blows the standard drill out of the water when it comes to driving screws and fasteners.
So when should I avoid reaching for an impact driver?
While impact drivers can be used for drilling holes, they aren’t the ideal tool for this task.
Drilling clean holes require a constant speed and torque throughout the process to achieve a good result. While impact drivers are capable of drilling, they generate powerful torque in short bursts that are jumpy and far from smooth.
Impact drivers also don’t use the same bits as regular drill/drivers. Impact bits require specially engineered hex-shaped bits that are designed to withstand the additional torque.
That means you won’t be able to use your standard drill bits inside your impact driver. Not only won’t they fit in the quick-change clamp, but they’d be far more likely to snap and break from the additional torque.
The good news is that if you’ve got an impact driver on hand, most likely you also have a standard drill/driver as well. The two tools are highly complementary to one another and are frequently sold together as a two-tool bundle.
Another area where you’ll want to avoid using an impact driver is when you’re working with pocket holes. As impact drivers are powerful, it’s easy to over-drive a pocket screw causing the screw to pop out the other side of the connecting board even if you’re being careful.
Over tightening a pocket screw can also cause the pocket hole itself to snap or break in half, leading to a lot of wasted time and effort.
You’re generally better off reaching for a standard drill/driver on a low speed/torque setting when driving these delicate fasteners.
Similar to the above example, when you’re using smaller decorative and hobby screws you’ll want to avoid reaching for the impact driver.
It’s easy to over-tighten shorter screws with an impact driver which can lead to cracking the wood surface or even snapping the head off your fastener leaving you with an unsightly embedded screw.
Instead, reach for a standard cordless drill for delicate woodworking fasteners – as this will give you a greater degree of control over driving speed and power.
Another thing to consider if you’re going to be doing a lot of delicate woodworking and finish work is using a smaller 12V impact driver. These smaller units are much better suited to handle smaller fasteners and are less likely to over-tighten shorter screws.
Another situation where you’ll want to avoid reaching for an impact driver is if you need to use a specific standard bit. Impact drivers require special hex-shaped bits, so standard bits often won’t fit inside their quick-change bit holders.
If you put a standard bit with a hex end in an impact driver, don’t be surprised if it snaps in half from the powerful torque.
Take this one with a grain of salt, but you’ll want to use caution when using an impact driver in hardwoods like oak, maple, or birch. As impact drivers generate a ton of torque, they’re more likely to break the head of a screw when it’s driven into these harder materials.
That doesn’t mean you can’t use an impact driver when driving fasteners into hardwoods, but you’ll want to be particularly careful with them when the screw head reaches the wood surface – as this is when break-off is most likely to occur.
Softwoods are a little more forgiving as the wood has a little more ‘give’ to it, so over-tightening is less likely to lead to a broken-off screw head.
This one might surprise you, but impact drivers are actually pretty loud. The short powerful rotational bursts of force generated by impact drivers make a lot of noise, and decibel-wise are closer to a hammer drill than a standard drill/driver.
If you’re working somewhere where you can’t afford to make a lot of noise, then you may need to reach for a standard drill instead of your impact driver. Regular drills don’t create the short powerful bursts of torque that impact drivers do, so they can be used to fasten a large number of screws relatively quietly.