Electric-powered breaker hammers have found a niche in the construction trades. In a wide variety of circumstances, these convenient tools fit the bill for small-scale demolition work.
Credit: Photo: by dotfordot.com
In our 30-plus years in construction, we've run into just about every kind of situation these tools were meant to handle. So for this test, we used them on a variety of demolition projects to see how they'd perform under different circumstances, from busting up commercial floor slabs to carefully chiseling grooves into vertical concrete surfaces.
We tested 12 breakers in three size/weight categories. The lightest , at about 25 pounds, are the brand new DeWalt D25941K, the Hilti TE905-AVR, Milwaukee 5339-21, and Wacker EH9BLM. The medium-weight, of about 35 to 40 pounds, are the Bosch 11335K Jack, Hitachi H65SD2, and Makita HM1304B. The heaviest breakers, of about 60 to 70 pounds, include the Bosch 11304K Brute, DeWalt D25980K, Hitachi H90SEKIT4, Makita HM1810X3, and the brand new Wacker EH27 Low Vib.
Out of the Box
The light and medium-weight models all come in rigid carrying cases, and a few have breaker points–generically called "tools" or "steel." The Makita and Bosch cases have small but nice integral wheels for easier transport on smooth surfaces.
The heavy breakers all come with a hand-truck-style cart, with the DeWalt being the best. Its removable holding pin on the tongue and large wheels meant it could be put into service hauling other things around the jobsite. It even has a hold-down strap and easy-opening posts to wind the cord around. All the heavy tools came with breaker points and chisels, too.
The lightest breakers in the test fit different shank-design tooling: the DeWalt takes 3/4-inch hex, the Hilti needs its own TE-S configuration, and the Milwaukee and Wacker units fit SDS-Max. The medium-weight and heavy breakers all accept 1-inch hex tools of the collared, slotted, or combination variety, except the Wacker, which only fits collared shanks. Breaker points and chisels aren't cheap; three or four of them can add more than $100 to a kit, but they can be reground when worn.
To begin the test, we gave each tool the same workout–breaking up a 4-inch-thick garage apron made of 3,000-psi concrete reinforced with polypropylene fibers–regardless of their weight classes. This let us get familiar with the performance of the tools relative to each other, and evaluate the functions of their trigger switches, variable speed controls, and handle types and to determine the vibration level each breaker imparts to the user–a very important factor overall.
For the second part of the test, we focused on the power and speed of each breaker in a series of timed trials. To find uniform, super-tough, reinforced concrete, we visited the boneyard of our local pre-cast concrete plant and spent a day pounding on some 4,000-psi concrete septic tanks and lids.
For the light breakers, we tested them in both vertical and horizontal applications. For the vertical surface work, we timed how long it took to score a 12-inch long by 3/4-inch deep groove into the wall of a tank. Next, we determined the fastest we could break through the 3-inch thick walls, which were armored with 6-inch re-mesh. Keeping the stopwatch going, we timed our progress until we had broken through a 2-inch diameter hole that we marked out beforehand.
The large breakers have either a fixed side handle, like on the Makita above, or a pivoting handle, like on the DeWalt. Pivoting handles are the first line of defense against felt vibration, but we felt that the internal anti-vibration systems were more effective.
Credit: Photo: by dotfordot.com
One clear observation is that only this lightest class of tools is truly suitable for vertical work. Adding the extra 10 to 15 pounds of the medium-weight breakers, plus their heavier tools, made them very difficult to hold up for very long.
Down on the ground, we went to work on a tank lid that was 6 inches thick and filled with a 6-inch grid of No. 3 rebar. Again, we timed our results, this time removing marked 6-inch square sections off the edge with each tool in the light and medium-weight groups. The challenge bested one tool: we stopped the midweight Hitachi after 6-1/2minutes of only light chipping. For the heavy tools, we measured how much material could be broken off a tank lid in five minutes.
The final phase of the test involved a day of breaking up a nonreinforced concrete slab of 4-inch thick, 3,000-psi concrete at an old warehouse site. We marked out an area for each tool and timed how long it took to break through the slab using a new breaker point. Again, the midweight Hitachi conceded defeat when it was only half way through the slab in 10 minutes; the other mid- and lightweight tools made it through much easier and faster.
We worked the heavy breakers for hours, ripping up dozens of square feet of slab, but we kept running into very comparable performance trials. Speed was not a big differentiating factor.
Another challenge was to cleanly score a groove 3-feet long and 1-inch deep into the slab, as if incising for a drain in a basement remodel. This tested breaker finesse and taught us a lot about handles, motor controls, bit positioning, and balance.