Q & A: Cordless Impact Drivers
What’s the difference between a cordless drill and a
cordless impact driver?
An impact driver is specifically designed to drive threaded fasteners. It’s especially
adept at driving large screws and lag bolts without pilot holes.
Smaller, lighter and more powerful than a cordless drill, an impact driver is the ideal
tool for cabinet installations, shop jigs and equipment and carpentry projects. Its
impact action keeps the bit buried in the head of the fastener, a great advantage when
driving screws from an awkward position.
A 12-volt impact driver is quite adequate for most woodworking. It’s twice as powerful
as a typical 18-volt cordless drill (880 in./lbs. of torque vs. 400 in./lbs.). Many
companies that make cordless drills also have a line of cordless impact drivers.
The chuck of an impact driver holds 1/4-in.hex-shank drivers,but can be used,with
an adapter, for sockets. Impact drivers spin screws more slowly than cordless drills do,
they cost $40 to $50 more and are annoyingly noisy.