Portable Electric Screwdriver
From DT Online
Power Drills with speed and Torque Control can be very effective also as powered screwdrivers but, more conveniently, a separate powered screwdriver can speed up working by avoiding the need constantly to change bits when drilling a series holes to receive screws. Such Drill Drivers are excellent when a constant Torque for precision work is required.
Features and Applications
The effectiveness of Powered Screwdrivers is enhanced if a hammer-type action is applied as the screw is turned. This is the case with an Impact Screwdriver but note that the hammer-action acts in the direction of rotation to increase torque and not along the axis of the chuck as is the case with a Hammer Drill.
Impact Screwdrivers are popular with Joiners working on construction sites with long, modern wax-coated and self-countersinking screws which cut their own way through softwood building timbers avoiding the need for clearance or pilot holes. Instead of a keyless chuck, Impact Drivers have a collet which accepts interchangeable bits with hexagonal shanks.