By Erik Elwell

Specs and Tester's Tester Comments

There is nothing quite as dirty, dusty, and plain-old tough as demolition work, especially for breaking up concrete and masonry. The work is unpleasant enough for both the crew and the tools so we try to get it over with as quickly–and as painlessly–as possible. But here in New York City, a town basically encased in concrete and rock, it's nearly impossible to avoid; we find ourselves starting virtually every job with heavy demolition. Our tool of choice for this work is the 20-pound demo hammer. It's heavy enough to break up hard stuff but versatile and light enough to work in a variety of positions and locations, and it still fits in the truck or gang box at the end of the day.

Test Criteria

On my sites, we break out–and through–a lot of concrete, block, and stone. We've tried heavier breaker hammers for this work, but they're too heavy and can often do more harm than good, sometimes resulting in busted pipes and cracked ceilings in the spaces below our projects. Plus, they're tough to store.

Hammers weighing between 18 and 22 pounds, however, hit the sweet spot. Their power-to-weight ratio provides the oomph we need for breaking up over-poured slabs and the agility and balance it takes for tough breaking jobs and surface cleanup. We sentenced five tools to 10 long weeks of jobsite testing: the Bosch 11316EVS, DeWalt D25900K, Hilti TE 805, Hitachi H60MRV, and Makita HM1202C.

We looked for raw power in straight-down jackhammer-like applications. Then we used them in front and overhead positions for break-through work opening block walls. We also used them in various positions for breaking down stone walls and cleaning up concrete surfaces where we sought the best-balanced tool with easy access to switches. Anyone who has worked with these tools also values vibration-dampening features, which we noted throughout the test cycle, as well as user-friendly bit-change mechanisms and kit boxes.

Pure Power

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DeWalt's in-line body design provided a direct punch to the bit.

Credit: Photo: David Sharpe

If a demo hammer doesn't have the knock-down power we need, all the balance and ergonomics in the world don't mean as much, so we hit them with the power test right from the start. We looked for raw strength first then comfort and vibration in some of our toughest straight-down chipping applications. We removed concrete topping (a 4-inch concrete layer on top of the slab) from an old building for a sixth-floor condo renovation. Think mountains of nearly 100-year-old super-hard concrete and days of chipping and you'll get the idea.

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Easy-to-access switches like DeWalt's are ideal for careful work.

Credit: Photo: David Sharpe

Straight-Down Power. After several days of straight-down chipping and several tons of busted up concrete, we found that the DeWalt performed best followed strongly by the Hilti. Each of these hammers broke through the topping and provided us with the chipping power we needed to muscle through. The Bosch and Makita had good showings, too, making quick work of the over-poured slab. The Hitachi seemed to lack the punch we were looking for even though it was one of the heaviest tools tested.

Body Type. The test group included tools with two different body designs, which also seemed to play a role in how they performed. We liked DeWalt's in-line design, which is similar to its larger cousin the jackhammer. With the bit and motor in line with the handle, it has good balance and control. All the weight is in line with the bit, which we felt helped it deliver all the punch directly to the working end.

The other tools' motors are offset from the center line of the tool. While we don't have the scientific equipment to quantify how this affected performance, our jobsite experience indicated that the tools with offset body designs had to work harder to remove material.

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Hilti's cushioned handle and great power combine to create one tough hammer.

Credit: Photo: David Sharpe

Bit Change. Breaking out an over-pour, as you would expect, we went through a lot of bits (see "Iron," page 56). Lifting up a 20-pound–plus tool and struggling with bit change is a sure way to get guys frustrated and slow the crew down. Thankfully, most of these tools have good systems, but some are better than others. We found the Hilti's bit change flawless and very easy to use. Bosch also has a good chuck but needed a little more effort than the Hilti to use. DeWalt and Makita came in a close third. Hitachi rounded out the pack with the most difficult bit change.

All the tools except the Hilti accept SDS Max bits; Hilti's accepts the company's TE bits.

Bit Rotation. All the tools tested allow you to rotate spade bits to customize the bit's orientation to the tool and the work for maneuvering in tight quarters. While we rarely use the feature, it's nice to have when you need it. The Bosch, DeWalt, Hitachi, and Makita require sliding a ring in the chuck back, then twisting the chuck to position the bit head. Detents let you know when the chuck is engaged. Hilti's octagonal TE bit works differently: To rotate it, you remove it and reinsert it into the chuck. Even though this does require an extra step, we use the feature so little that it's not a big deal. And, fewer moving parts in the chuck may prove beneficial in the long run.