D-Handles & Triggers

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Metabo's electronic control indicator blinks when brushes need to be replaced.

Credit: Photo: David Sharpe

D-handle rotary hammers in this compact class are said to outsell pistol grip-configured tools in the U.S. market, and there are a few good reasons this might be so. The enclosed grip does offer your trigger hand some protection from nearby objects such as jagged rubble or protruding rebar when drilling and chiseling, especially when suddenly punching through hollow block or unexpectedly having your chisel skitter across a wall. But the main benefit is having the force applied by your trigger hand much more in line with the center of rotation and hammering. With the tool handle directly behind the bit, you can apply all the force you need while having your index and middle fingers comfortably wrapped around the trigger, not having to rely on only your lower fingers like when using an in-line grasp with a pistol-grip tool, giving you greater control.

All the tools in our test offer a large trigger in a D-handle that is easy to pull and hold while working, but the DeWalt and Metabo provide a little extra hand room around the trigger, which definitely comes in handy on cold winter days when thick gloves can make all the difference between misery and productivity.

Another trigger feature that can really help you during lengthy, repetitive drilling chores is the lock-on button. With the motor continuously running at full speed without a finger on the trigger, you are free to change positions and readjust your rear hand to change pressure on the tool and reduce stress on your hand and wrist. This feature is available on the Hitachi, Makita, and Metabo models.

Surprisingly, the largest variance in the group regarding triggers comes from their reverse features, even though reversing is usually only done when freeing a bound bit. (See "Reverse Logic," page 52).

Ergonomics

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All the tools in the test except for the Metabo come with easy-to-use slip-collar chucks for quick bit changing, as seen here on the DeWalt.

Credit: Photo: David Sharpe

Maybe I'm getting older and a little tired of working around hard concrete, but for me comfort and ease of use have become as important as any criteria in my tool selection, and they affect my perception of performance. Drilling and chipping concrete is a noisy, dirty business, and the better a tool combines power and comfort, the better it is for the user. So you just can't judge a tool like a rotary hammer without considering ergonomics, and it played a big part in our evaluations on the jobsite.

When we looked at ergonomics, we concentrated on grips, vibration, and noise. All these rotary hammers have rubber-cushioned rear grips, which we felt helped out with controlling vibration and minimizing hand fatigue. As far as handle comfort is concerned, the Metabo was our favorite, with an octagonal rubber grip on the side handle that definitely had the best feel. Bosch also has a rubber-paneled side-handle grip, though it was not quite as comfortable as the Metabo.

The other three models all have hard plastic side handles. Even though the DeWalt side handle is not padded, it is flared out on the bottom, which helps keep your hand on the grip. The Makita and Hitachi have adequate side handles. Makita's has a unique feature: teeth that mechanically lock the side handle in the desired position on the nose of the tool; it's a little more work to adjust, but once it's on, it won't rotate around the tool, even if the handle is a little loose.

As far as overall vibration and noise are concerned, Metabo vibrated the least and was the quietest, followed by DeWalt, Bosch, Makita, and then Hitachi.

Power

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The large octagonal rubber grip on the Metabo tool's side handle made it the most comfortable.

Credit: Photo: David Sharpe

All the tools in the test performed well and each held up to the rigors of pounding and drilling concrete on the job, so we performed a side-by-side test with all the tools using new, identical 1/2-inch SDS-Plus bits to determine any performance differences. Using our jobsite conditions, we drilled a series of vertical and horizontal holes in reinforced concrete and then moved on to fieldstone.

The Hitachi was tops in terms of raw speed, getting the job done quicker in terms of drilling and chipping, but its vibration and noise quickly became annoying, and we didn't like sacrificing comfort for the speed delivered. Bosch, DeWalt, Makita, and Metabo were virtually identical in terms of power and all had the ability to get the job done; however, the Metabo seemed to have the most consistent power over the range of material, most likely due to its unique electronic speed control feature that works to keep its rpm constant even under load.

We also liked the "health" control on the Metabo, which blinks a warning when the tool gets too hot or the brushes become worn. It's a nice feature I am sure will add life to the tool over the long haul.