Disclosed is a fixed carrier type coil insert tool for installing a threaded insert into a threaded aperture of a workpiece. The insert tool is designed to provide means for externally adjusting the depth to which the coil insert is installed within the workpiece. This is accomplished by providing a carrier whose position relative to the mandrel can be adjusted so that the distance from the end of the mandrel to the workpiece is adjustable. Since the mandrel advances a fixed distance upon actuation of the power tool, the result is a change in the depth of penetration of the mandrel into the workpiece, and a corresponding adjustment in the depth to which the coil insert is installed into the aperture of the workpiece.