DeWALT 18V Ni-Cad Cordless Impact Wrench (DW059K-2)

Impact wrenches are the heavy weights of fastening tools. Unlike other tools that may have multiple applications, they're pretty much single focused - they excel at installing and removing nuts and bolts. You'll find them in a range of sizes; 1/4" drives for chores around home and shop, and up to 3" drives for heavy duty industrial use. They also come in pneumatic, corded and cordless formats. They're quite similar in design and function to impact drivers. However, impact drivers have hex chucks (typically 1/4"), and are used primarily for driving lag screws and setting nuts. An impact wrench has a square drive (3/8" and larger), and is used primarily for driving impact sockets. While you'll find a lot of carpenters, remodelers, woodworkers and avid DIYers using impact drivers, impact wrenches are primarily found in machine shops, garages, at industrial and large commercial work sites, and in the tool kits of avid car enthusiasts.

The DeWalt 18V Ni-Cad Cordless Impact Wrench is a heavy duty tool with a 1/2" drive. It delivers an impressive 300 foot pounds of torque at speeds of 1,650 RPM and 2,600 BPM. There is no variable speed - the wrench runs at full speed or not at all. Likewise there isn't an electric brake. The DW059 has an internal spring-loaded pulsating cam that serves to create rotational torque. Creating all this force generates a fair amount of noise - you'll find that the impact wrench is louder than a drill/driver or impact driver.

With this kind of power you can inadvertently cross thread a bolt or over-torque a bolt or a nut. It's a good idea to begin threading bolts by hand, and once the threads are aligned then use the impact wrench. There isn't a torque control on the DW059, which stops the drill when a specified torque level is reached. So it's best to continuously check to ensure you haven’t over-tightened. You'll be surprised at how quickly the impact wrench can remove and re-install the lugs on your car or truck.

High impact ABS body and rubber overmold handle

Rocker style trigger

The body of the DW059 is made of a high impact ABS plastic. A rubber overmold provides some cushioning on the handle. At just over 7 1/2 pounds it's a heavy tool that will quickly build up arm muscle if used for hours on end. Fortunately it's typical used intermittently rather than continuously. It uses a large rocker style trigger. Press the bottom part of the trigger and it runs forward (clockwise rotation); press the top part of the trigger and it runs backward (counter-clockwise rotation). Getting used to this type of trigger takes a bit of practice, but it's not overly difficult to learn. The large size of the trigger makes it easy to use with gloves on.

Any abuse to the tool takes place at the front end, and DeWALT has done well by using die-cast magnesium alloy for the  gear case housing. The 1/2" drive has a detent pin that securely holds sockets in place. Occasionally it's hard to get the sockets off; you need to depress the detent pin, which can be a bit of a chore.

The DW059 comes with two 18V XRP (eXtended Runtime Performance) Ni-Cad batteries (DC9096). These high capacity 2.4 Ah batteries hold a charge extremely well (DeWALT claims a 40% longer run time than other Ni-Cad batteries). The run time you you get will obviously depend on tool usage, but we've noticed a marked improvement over the older DeWALT batteries.

Magnesium housing and 1/2" detent drive

The DW059is compatible with either 18V NiCad (L) or 18V Li-Ion (R) batteries

The DW059 also comes with a 1 hour charger (DW9116), which can charge 7.2V to 18V NiCad batteries. It features DeWALT's 'Automatic Tune-Up Mode', a technology that balances the individual cells in the battery so that it can function at its maximum capacity. Once every week or 10 charge cycles (which ever comes first) you simply leave the battery in the charger overnight. Charging is complete when the red light on the charger remains on continuously.

You can also run the DW059 on an 18V XRP lithium-ion battery (DC9180) - it shaves 3/4 of a pound off the tool weight. For those of you who have multiple DeWALT tools that run on either NiCad and Li-Ion batteries, the DC9310 charger will be of interest. It enables you to charge all DeWALT 7.2V to 18V batteries - NiCad, Li-Ion and NiMH.

As with most DeWALT tools you get a decent had shell case that works well. It's easy to put the impact wrench back in the case for storage, along with batteries, charger and a load of impact sockets. The instruction manual is printed on a 20" by 34" sheet of paper, making it very awkward to unravel.

What the DW059 may lack in refinement it makes up for in dependability, power and reliability. And the XRP batteries provide excellent run time. This is a great tool for any professional or layperson who needs to fasten tough nuts and bolts.

Reviewed July 2010