Impact Drivers

Mechanics have long known the benefits of an impact driver. Pneumatic impact drivers have been used in auto repair for many years for their ability to deliver considerable power and torque to the object being driven without transferring the power or impact to the operator. This made them ideal for use in tire shops for removing or re-installing lug nuts, a task that was rather arduous using a lug wrench but one that almost became child's play with an impact driver.

Not so long ago, the same type of technology was tested in cordless drills, and the cordless impact driver was born. Now today's small, handheld cordless impact drivers probably don't have the torque to handle removing or reinstalling the lug nuts on your car, but they are incredibly versatile not only in the woodshop, but also around the house.

Can you use an impact driver as a drill? Absolutely. Matter of fact, drilling clean holes with a spade bit is actually much easier with an impact driver. One of the problems with drilling large diameter holes (1/2-inch and wider, up to about 1-3/8 inches in diameter) with a spade bit is that the bit can pinch and get hung up in the hole. When the bit gets stuck in the hole with a cordless drill (or worse, a heavy-duty high-torque power drill), rotation that the motor was applying to the drill bit and chuck is then transferred to the body of the drill, twisting the drill in the user's hands. In the best of cases, the drill will slip out of the operators hands, or worse, the twisting drill's torque can be transferred to the operator. I can't tell you the number of times I've hurt my wrist from having a spade bit stick in the hole.

With an impact driver, the potential for such an injury is reduced considerably. The start and stop motion of the driver's action applies torque in powerful, but small bursts, helping to keep the spade bit from sticking. Even when it does stick, the amount of torque kicked back to the operator is minimal. This makes the impact driver a perfect tool for electricians and plumbers, who need to drill a number of 3/4-inch and larger holes through studs for pathways for wiring and pipes. For anyone who has experienced a sprained wrist from repeatedly having a power drill wrenched in their hands, using an impact driver for the same task is a godsend.

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