By Erik Elwell
Publication Date: September/October 2002
Cordless tools improve every year. If it's not battery performance, it's power -- or new features, switches, or advanced charging systems. The hammerdrilling function, one of the latest and best improvements to cordless driver/drills, makes them even more valuable on site. The ability to quickly switch to hammer mode from drill mode and back again saves trips to the gang box for a cord and new tool.
Test Criteria
I tested 14 of the newest cordless hammerdrills to see if their power, performance, and other features were on par with their convenience.
Out of the box, each tool looked solid and nicely put together. It shows that the race for cordless drill superiority is a tight contest among manufacturers. I tested tools in five voltages: 14.4, 15.6, 18, 19.2, and 24.
The 14.4s included the Bosch 3670-04, DeWalt DW984K-2, Makita 8433DWDE, Milwaukee 0514-24, and Porter-Cable 9877. Metabo's SBT15.6 Plus and Panasonic's EY6931NQKW were the 15.6-volt entrants. The 18-volters included the Bosch 3870-04, DeWalt DW988K-2, Hitachi DV18DV, Makita 8443DWDE, and Milwaukee 0524-24. Porter-Cable's 9887 was the 19.2-volt tool. The 24-volter was Hitachi's DV24DV.
Drilling Power
The great thing about a cordless hammerdrill is that if you need a hammer function to set a junction box on a concrete ceiling or set expansion bolts for attaching to masonry, you've probably already got your cordless drill out anyway for driving screws. Now, you can use the same tool for the whole shootin' match.
Using 1/4-inch, 3/8-inch, and 1/2-inch masonry bits, I drilled a series of 1-1/2-inch-deep holes in 2,500-psi concrete until each tool's batteries ran out of gas. With 1/4- and 3/8-inch bits, the tools drilled so many holes I lost count. Drilling with the 1/2-inch bit, however, let me evaluate power, feel, and how many holes these tools can drill on one charge. For this part of the test I put the tools in three groups: low, medium, and high volts. (The Metabo and Panasonic 15.6s went in the low-volt group; the Porter-Cable 19.2 joined the medium-volters.)
All the drills in the low-volt group drilled 14 to 16 holes. The 15.6-volt Metabo and Panasonic tools have a slight power edge. The medium-volt group drilled 19 to 21 holes each. The 19.2-volt Porter-Cable model had more power than the 18-volt tools in the group, popping two to three more holes.
In a class by itself, the Hitachi 24-volt not surprisingly outperformed all the others by nearly 35 percent. It hammered 24 to 26 1/2-inch-diameter holes on a single charge. While the other tools in this group are drill/drivers with a hammer function, the Hitachi 24-volt tool is the only dedicated hammerdrill in the group. It's designed to compete with your corded hammerdrill and, considering its performance, size, and shape, it does. The portability and easy set-up of this tool make it a natural for most projects requiring heavy, but not too heavy, hammerdrilling.
For hardcore wood drilling, the 24-volter goes hard. It easily sent a 2-inch boring bit through a 4-by eight times. I was up to my ankles in wood chips before the tool quit. As for hard pounding, I'd go to this tool first if I had to drill a deep hole for sending wire or conduit through a brick or block wall or setting lots of 1/2-inch lag shields.
Vibration and Comfort
The hole-drilling test highlighted important differences between the tools. In all voltage groups, the DeWalt, Porter-Cable, and Bosch drills performed the best. They show minimal vibration and little slowdown, especially when they hit tough spots like aggregate. The heavier-feeling Bosch 18-volt model came in at the tail end of this first group. Next, I liked both Makitas, then both Milwaukees and the Panasonic tool. Hitachi's 18-volt tool and the Metabo 15.6-volter finished up in order.
The 24-volt Hitachi felt good drilling, too. Its long body makes it tough for overhead applications, but great for floor drilling. This isn't a tool that you'd do any screw driving with.
Chucks
A hammerdrill's chuck quality is important. The chuck has to spin the bit while a gear in the tool housing impacts it somewhere between 15,000 and 30,000 times a minute. Thank-fully, the new generation of keyless chucks can quickly grab and hold just as powerfully as keyed chucks do.
Hands down, Bosch and DeWalt have the best chucks on their 14.4- and 18-volt tools. Both manufacturers use an impressive Rohm chuck that grabs the bit and centers it quickly, then locks it in place with a ratcheting mechanism. This mechanism delivers great holding power without the usual forearm-busting, two-hand twist. They also have slip rings on the front that allow you to contact the work piece if you're drilling in a corner without grinding the chuck into it. Metabo's chuck also has a slip ring.
Both Milwaukee tools also have good chucks. They feature all-metal construction and impressive holding power. The metal adds a little weight, but I can accept that because the chuck sees so much action. Both Porter-Cable tools, both Makitas, the 18-volt Hitachi, and the 15.6-volt Metabo did well in the chuck category. They all performed fine; no bits slipped when properly set and all held on tight when the going got rough. The only concern I had was the amount of plastic on these chucks.
Panasonic's 15.6-volt tool has an interesting chuck. The housing slides up and down. This releases a locking mechanism, which ensures that the chuck stays tight all the time. It took a little getting used to, but it sure beats losing bits when you hit reverse.
Ergonomics
Switch location, ease of use, and overall ergonomics can be a tool's greatest selling points. I want a tool that I can use all day without struggling to change functions or settings. The less effort it takes to go from high to low gear, from forward to reverse and all the variable torques, makes a tool that much more useful.
Both DeWalt drills fit my hand well. I have average-sized hands and the switches were always in the right spot for me. Both of the Bosch tools and both of the Porter-Cable tools are next in comfort, with Hitachi's 18-volt tool after that. Panasonic, Milwaukee, and Metabo units finish it up with Makita a disappointing last. The tool has great switches and battery interchange, but the grip didn't work for me. The hard black plastic wasn't comfortable in my hand and got sweaty and slippery after pounding all those 1/2-inch holes.
Cool Features
The slip rings on the Bosch and DeWalt chucks not only protect your work, they're also helpful when drilling in tight spots and actually make bit installation easier. I really like this feature because I tend to change hammerdrill bits often when I do several tasks like driving screws or drilling wood and concrete. DeWalt's drill has three torque settings -- high, medium, and low. I won't use the medium setting every day, but I'd use this feature for certain applications like driving brass screws where speed and torque control are essential.
Milwaukee's battery is reversible, which alters the drill's balance and configuration. When working in tight spaces, this enables the battery to take up less room. Metabo's pulse rotation switch helps loosen overly tight screws. I had to go on the Internet to find out what this switch was for, because it's not in the owner's manual. It makes a difference, though, when backing out tough screws, because the screw head doesn't strip as easily. I can see this coming in really handy if you have to get a cabinet off the wall and the screw head is a little reamed.
The Winner
When I buy my next cordless drill, I'll definitely buy one with a hammerdrill feature. It makes the tool more versatile and valuable on site. There's no trade-off of weight or function for the benefit either, other than a slightly higher price tag. Since I get into enough stuff that requires larger holes, an 18-volt tool is right for me.
That said, DeWalt's DW988K-2 18-volt cordless hammerdrill is my pick. It's got impressive ergonomics, power, and performance, and it's reasonably priced. Bosch's 18-volt drill comes in a close second. Even though it's a bit heavier, it's a great tool that's easy to work with. Porter-Cable's 19.2-volt drill comes in third; it's a good, reliable, solid tool. In the 14.4-volt group, the order is the same -- DeWalt, Bosch, and Porter-Cable -- as the tools are nearly identical.
Sharing the next spot are both Makitas, the 18-volt Hitachi, both Milwaukees, and the 15.6-volt Panasonic -- they all performed about the same. Metabo rounds off the pack.
The 24-volt Hitachi is in a class by itself. With its power and dedicated design, you've got a ton of cordless power here.
is a Manhattan-based contractor specializing in high-end commercial and residential remodeling.
Hanley-Wood's Tools of the Trade has arranged with the companies in this test to donate their tools to Habitat for Humanity.
Thanks to American Tool for providing all the bits for this test.
This article is reprinted courtesy of Tools of the Trade
