Step 6: Installing Hardware (Screw)
Determine the diameter of your screw head and drill a recess in the top of your knob just deep enough so that the head of the screw is completely below the surface. This is for aesthetic reasons. If you don't mind the top of your screw sticking up you can skip this step.
Begin screwing the screw into the knob. The treads on a machine screw aren't really designed to cut into the wood so it may be difficult. If you find it too difficult you can remove the screw and enlarge the central hole.
When the screw is most of the way in but before the gap is closed completely you can put a few drops of super glue into the screw head recess. This will allow the knob to hold onto the screw much better and is required if the screw is loose within the central hole and is highly recommended when making knobs from softwoods that won't grip the screw very strongly.
Tighten the screw the rest of the way and set aside to let any glue that you've added to dry.
Once you have installed hardware in all of your knobs move on to the finishing step.