Core drill in HSS with roof tip and spring-loaded guide sleeve, self-centering hinge drill for use in hand drills, the guide sleeve is inserted into the screw hole of a hinge or fitting and drilled while the machine is running, the guide sleeve of the hinge drill centers itself automatically in the screw hole of the hinge or fitting, precisely centered With the larger hinge hole, you can create the core hole in no time at all and then use a screw to attach the fitting to the component