TIM UHLER

Full-size, heavy-duty cordless drill/drivers aren't the right-hand-man to builders and remodelers they once were.

Many pros find they can get the power they need for typical driving and drilling tasks with a 10.8-/12-volt subcompact drill/driver. Higher efficiency motors and amp-hour packed lithium-ion batteries can make a lower voltage tool a thing of wonder, with power and runtimes surpassing some pro-grade 18-volt tools of just a half-dozen years ago.

Efficiency-minded tool buyers also have a large range of compact 18-volt drill/drivers to choose from that are only two-thirds the weight and bulk of the big boys we chose for this test. And along with the newfound strength of smaller drill/drivers, impact drivers represent another and increasingly popular option.

So, is there a good reason to buy a full-sized hammer drill/driver and carry around more tool than you may need? There is. You're still likely to carry a corded 1/2-inch drill in the truck to bat cleanup for heavy-duty tasks your everyday cordless tools can't tackle, so why not go cordless? The best of the tools in this test have the capability to power through just about anything that intimidates a lightweight "daily driver," and all without having to run a power cord.

For those who keep only one drilling and driving tool around, these full-size tools make a good choice. They can handle everyday jobs and still have enough reserves for high-demand tasks in wood, metal or masonry.

Sizing up the field of full-size models

A lighter cousin to the more powerful rotary hammer, a hammer drill gets its name from the rapid hammering action it applies to the bit as it rotates, helping it pulverize hard materials like concrete and masonry. The hammer function may not get used all the time, but it's there whenever you need it. Users can switch between three modes on these tools: drilling, clutch-controlled driving, and hammer drilling.

I sought out powerful, full-size 18-volt hammer drill/drivers for this evaluation. If a brand had two models, I picked the newest one. To make sure the tools had the greatest potential versatility, I only included those with a hammer drill feature. This adds a little weight and a little cost, but the increased versatility is worth it for many contractors.

For those with no need for the hammer drill feature, most of the tools also are available as a standard drill/driver, usually with the same specs and features. If a company has a similar drill/driver or hammer drill/driver with a higher torque rating than the tool in the test, I note that model in the comments of the specs section.

Besides being useful for boring big holes, these tools also excel in a few fastener-driving applications. An impact driver or an impact wrench is usually the tool of choice for large fasteners, but for long, springy screws or lags, these tools can put all of their power into repeatedly flexing the screw shank without making much progress in driving it.

What you need for these fasteners is the constant torque applied by a drill/driver, which loads the screw shank until it starts moving and never lets up until the job is done. A smaller drill/driver may not have enough power, and a corded drill may not have a slow enough speed to do this job well.

Brushless motors and electronic control functions

Six of the ten tools in this test have brushless—aka EC, electronically commutated—motors. Brushless motors require less maintenance, and are more compact, but their real benefit is greatly increased runtime on a single charge because of their higher efficiency.

Another benefit of electronic commutation is the computer chip that regulates the motor also can apply precision control for speed and clutch settings. Hitachi has four electronic speed settings that control the maximum rpm of the trigger. DeWalt features an electronic clutch action. And Festool and Metabo have these functions combined so a lower clutch setting also results in a slower rotational speed.

In use, the speed control feature is largely a gimmick because reducing the pull on the trigger or shifting the tool into low gear can produce the same effect. An electronic clutch has both benefits and drawbacks. Unlike a typical friction clutch, which continues to drive a fastener slightly even as it's slipping, an electronic clutch shuts off the motor instantly when it reaches its torque setting. This makes it too finicky for driving fasteners into wood. You'll have to set the tool to a higher torque level than you need to get reliable driving results.

Removable chucks

In classic European fashion, where tools are costly and space is at a premium, Festool and Metabo feature interchangeable chucks that let one tool serve multiple uses. You can attach separate accessory, heads such as a right-angle drive, a gear-reducing torque multiplier, or even just a simple ¼-inch bit holder that is more convenient than a drill chuck for most driving uses.

Battery capacity is growing

Escalation of the battery amp-hour race continues unabated, with most of the tool brands having upgraded to 4.0 Ah batteries in the last year as the standard battery pack for many of their newer and stronger tools. Metabo led the way with 5.2 Ah batteries, available since 2013, and Festool and Makita are premiering their 5.2 and 5.0 Ah batteries respectively with their new tools out just in time for this test.

Hitachi is still using 3.0 Ah battery packs, and Hilti's are 3.3 Ah. However, since the Hilti packs are 21.6 volts, they contain the energy equivalent to a 4.0 Ah battery at 18 volts.

Most models have side handles

Hammer drill/drivers with as much power as these really need a side handle to help manage their drilling and driving torque safely. Besides safeguarding your wrist whenever a bit jams or a big fastener is seated, a side handle makes two-handed use of the tool more ergonomic.

Most of the tools come with side handles proportional in length to their output torque, so I was immediately skeptical of the heavy-duty status of the one tool that didn't include one.

Though formerly standard gear with any hammer drill/driver, stop rods to set drilling depth were only included with the Bosch, Festool, and Makita. This is curious because all of the side handles still have dedicated slots for stop rods.

Belt hooks

Though a minor feature, a belt hook is a nice thing to have on a drill/driver of any size. After using the tool, it's handy to be able to clip it directly to your belt instead of finding a place to set it down. Having the tool with you keeps you more productive.

The bottom line

Because hammer drill/drivers this large are unlikely to be in your hand all day, the most powerful tools get the nod as the best performers. I was looking for the heavy hitters with the muscle to handle jobs smaller drill/drivers can't.

The tool that best exemplifies this pedal-to-the-metal horsepower is Makita's new XPH07T. It dominated the field by posting the fastest times in every power challenge of the test as well as topping the run-time ratings. Winning all of the time trials shows the Makita has power to spare and can perform the same work faster than the other tools. Best in power, application speed, and runtime make this tool a real winner.

Next are the tools from DeWalt, Metabo, and Milwaukee. These tools kept up the pace through the toughest work, and also were at the top of the runtime ratings. Festool and Hilti rank next. They could perform most of the heavy lifting but their four- and three- speed gearboxes (respectively) meant that their low gear application speeds were slower than the most capable tools.

The Bosch is right at the edge of earning a place among these truly heavy-duty tools, but the Ridgid, Hitachi, and Fein didn't quite make the grade, trailing the rest throughout most of the tasks.

Michael Springer is the former executive editor of Tools of the Trade.