By altering their products inside and out, manufacturers are creating tools with reduced vibration levels. This encourages worker comfort, safety, and productivity, along with making tools more efficient.

GOOD VIBES: Clockwise from left: The 5363-21 rotary hammer from Milwaukee uses vibration-reducing handle construction and soft grip handles; Bosch's RS35 reciprocating saw also uses vibration-reducing handles; Hitachi's G18SCY 7-inch and G23SCY 9-inch angle grinders feature vibration-absorbing main and side handles. The rising awareness of hand-arm vibration syndrome, which workers can get if overexposed to vibration, drives the protection trend. The syndrome causes numbness, whiteness and pain in fingers, and a reduction in grip strength and finger dexterity, according to a report by the National Institute for Occupational Safety and Health. Symptoms "increase in severity as exposure to vibration increases in intensity and duration," the report says.

In 2002, the European Union limited vibration exposure. If a tool's rating reaches above 5 m/s² (meters per second squared), a worker could not use it for the whole day. If a tool vibrates at 10 m/s², a worker could only use it for two hours.

Many of the European-based tool companies responded to the standard by lowering products' vibration. Less vibration means customers can use tools longer, says Terry Tuerk, a product manager at Metabo.

Reducing vibration also makes tools more efficient, says Anthony Corwin, a product manager for Makita. "Some tools without [anti-vibration] protection are going to vibrate much more and actually take away drilling and impact energy from the bit of the tool," he says.

Manufacturers are changing tools in two ways: improving handle construction and using internal weights.

Anti-vibration handles work to "separate the handle from the rest of the machine," says Jim Bohn, a product manager for Bosch. Or, they can help to absorb vibration.

Counterbalance weights work like counterweights on tall buildings in seismic areas, says Joe Fedor, a product manager for Hitachi. "As the top of the building moves one way, the counterweight moves in the opposite direction to counter the weight of the building," he says. "As the hammer strikes the bit, the counterweight works in the opposite direction."

Hitachi's 7- and 9-inch angle grinders use vibration-absorbing main and side handles to reduce vibration levels by 25% from previous models, the maker says, resulting in a rating of 3.3 m/s². The company's 12 Amp reciprocating saw uses a counterweight to reduce vibration levels by over 65% from previous models, the maker says, giving the product a rating of 9 m/s².

Bosch put anti-vibration handles on its reciprocating saw to give it a rating of 4.5 m/s², 50% less than competitive models, the maker says.

Bosch also uses vibration-reducing handles on its new random orbit sanders; Metabo does so on its KHE 56 SDS-Max rotary hammer; this protection is in Milwaukee's compact SDS rotary hammer; and DeWalt uses such handles on its 1-inch SDS hammers.

Hitachi also uses counterbalance weights on its new SDS Max rotary hammer. DeWalt's new heavy-duty demolition hammers use floating handles and counterbalances. Makita incorporates counterbalances in its expanded line of concrete hammers, which includes a variety of rotary hammers.

Concentrating on worker safety and comfort, anti-vibration technology lets manufacturers strive for equilibrium between a tool's power and efficiency.

"You can make a tool faster or hit harder," says Corwin from Makita. "But what will make a difference is how the guy who leaves the job site feels after working for eight hours. It gives the end user a much better life after work."

–Victoria Markovitz