From file "073_pss" entitled "PMONIdec.qxd" page 01
From file "073_pss" entitled "PMONIdec.qxd" page 01

You've no doubt heard the phrase “Don't judge a book by its cover.” The same principle can be applied to cordless impact drivers, compact power tools that pack a lot more punch than their small sizes might indicate.

Cordless impact drivers aren't new necessarily, having been around in the United States since the late '80s. But recently the category has witnessed an explosion as more models are introduced, more companies get in the game, and more contractors take notice. “Since then, it's been an evolution,” says Makita marketing brand manager Brent Withey. “Every year, the technology keeps on changing … more power, smaller piece, more features.” Makita's line includes four new models this year.

Impact drivers look a lot like small drill/drivers and can be used for fastening into a variety of materials with everything from drywall screws to lag bolts. Impact drivers are as much as one-third smaller than an equivalent voltage drill/driver and are lighter. And despite their smaller size, cordless impact drivers actually produce as much as three times more torque, manufacturers say.

The difference is in the connection between the motor and the output shaft. Unlike the direct drive–type mechanism in drill/drivers that produces in-line torque, impact drivers feature an internal hammer action that delivers rotational torque, generating greater driving power in a smaller package, as well as more control. And since there's no direct connection between the bit and the motor, users feel less of the torque of the tool and have to apply much less force to the tool to drive fasteners in.

“You're getting all of this torque out of the bit, but the user doesn't feel any of that torque, it's all in the hammer action,” says Steve Steadings, director of product development for Ridgid, whose offerings include a right-angle impact driver.

“There's been this desire for something smaller and lighter, and that's really what's been driving this,” says Jeff Wilkison, director of cordless marketing for Bosch, which has introduced the Impactor line of impact drivers.

Impact drivers do have some drawbacks however, the most noticeable being their loud noise. In addition, some impact drivers are limited to fastening applications. Some manufacturers, however, recommend their tools for drilling. Hex-shank bits are required for drilling, although chuck adapters are available for some tools to accommodate round-shank bits.

While many contractors are already using impact drivers, not all understand the differences. For dealers, the best way to promote the category is through demos. “Once the user sees it demonstrated, he's definitely going to see the benefits, be it the size of the unit, the speed of completing an application, or the torque that is generated,” says Brian Hendricks, group product manager for DeWalt, which offers several models.

“Dealers can tell their end users, ‘This tool has three to five times the torque a normal drill/driver has, it's much lighter, it's also much smaller in size, so you're going to be more productive with a much smaller tool,” says Kevin Fairchild, product manager for Hitachi, which makes a range of impact drivers.

Impact drivers also are available from Milwaukee and Panasonic.

As more contractors realize the benefits of impact drivers, manufacturers believe the category will continue to expand. Growing interest on both the vendor side and the customer side should keep technology moving and interest soaring.

The internal hammering action of impact drivers delivers more torque in a smaller package. Photos: Ridgid, DeWalt