By Rick Arnold
As a self-employed contractor in New England for nearly 30 years, I've relied on rotary hammers for as long as I've been in business. As a concrete foundation contractor, I've used them to drill holes for placing rebar into existing foundations to tie into a new pour, and occasionally on new foundations to chisel out a misplaced or forgotten beam pocket or utility chase. These days, with my projects ranging from residential remodeling and new construction to light commercial work, I use them less often but for more varied tasks like drilling for missed anchor bolts, installing deck ledger bolts into foundation walls, chiseling out old concrete firestops, creating holes for conduit, and especially tying new foundations into old.
Recently, my 25-year-old corded rotary hammer cranked out its last hole. And, like most guys, if I can replace a corded tool with an effective cordless one, I'm all for it. So this tool test came at a perfect time; it gave me an opportunity to use and compare some of the latest cordless rotary hammers.
The concrete drilling capacity of the models I compared ranges from 3/4 inch to 1 inch and their batteries from 18 volts to 36 volts. I compared nine tools in four voltages: Three 18-volt models–the DeWalt DC212 KA, Makita BHR240, and Metabo BHA18–the 24-volt Panasonic EY6813NQKW, the 28-volt Milwaukee 0756-22, and four 36-volt models–the Bosch 11536VSR, DeWalt DC233 KL, Hilti TE 6-A LI, and Hilti TE 7-AC. I also tested a 10th tool, the smaller Panasonic EY6803GQW 12-volt combination rotary hammer/driver, which I used alongside the others but review separately at the end of this article. All of these new tools fit common SDS-plus bits, and all but the Panasonics and the 18-volt DeWalt have lithium-ion (LI) batteries.
Out of the Box
Cases. Since I store tools in side- and under-mount truck boxes, I need the case to be compact, but I also like to use the case to store bits. Panasonic's case is too tightly packed to store anything in it, and Makita's is almost as cramped. Most of the rest provide adequate bit storage with dedicated compartments; the Milwaukee is the best of the bunch with a separate compartment in its lid with a latching door. The Hilti cases are almost too large, and their lack of enclosed storage means bits rattle around.
Batteries and Chargers. All of the kits come with two batteries and a charger. Nicad batteries also can be used in the Hilti models, but I tested the tools with the most common LI batteries sold with each. The Metabo also can be used with nicad batteries, but it is not sold with them in kit form in the U.S.
One of the nicest new features on the Bosch, Hilti, Metabo, and Milwaukee LI batteries is a lighted charge indicator. With the push of a button, it lets you know how much charge is left rather than having to find out the hard way in the corner of a crawl space.
All of the batteries–whether they were the tower type or the slide type–clipped in solidly, but Panasonic's hold is reinforced with a snap-in metal band across the bottom. This seems like good insurance given that these vibrating tools probably hand out more abuse to their clips and clasps than any other tool.
The Milwaukee charger plug has a piggyback outlet that came in handy more than once–a simple yet very useful feature.
Accessories. A side handle is standard with each tool, and all but the Metabo come with a depth-stop rod. Both Hilti tools come with quick-disconnect bit holders that can be replaced with an accessory drill chuck, plus dust blow-out bulbs, small dust-collecting cups, and bit grease. The Panasonic includes a unique accordion-style dust collector and bit grease.
Mode Selection. All of these rotary hammers have a hammerdrill mode and a drill-only mode. The Bosch, DeWalt 36-volt, Hilti TE 7-AC, Makita, and Milwaukee also have a third chipping or chiseling mode. And these five tools have a spot on the mode selector that allows for manual setting of the chisel angle. For my money, I prefer to have a model with the chipping feature for the dual use of a single tool, but not everyone uses chipping in their work, especially with these smaller rotary hammers.
A feature unique to the Panasonic is its speed/blow selector that shifts between high and low settings for both rotation speed and hammer-blow power. This allows the user to lower the output speed and impact but keep the motor torque high, unlike just using a variable-speed trigger that lowers the rpm and power together.