Tapping on a Drill Press
A drill press is the ideal solution when boring an initial hole and tapping it. You will need attachments to make it possible to tap on a drill press, as most presses are not set up for this. You must have proper hole width and establish concentricity to accurately tap a hole. It takes a bit of practice to get it right so be patient and keep trying.
How to Tap a Hole
Begin by drilling the initial hole on a drill press to ensure accuracy of the diameter. Then prepare the drill press for tapping by adding a tapping attachment. Using a center finder, you then place the point on the chuck to line up the center of the spindle with the hole.
From there, you can select your tap type, choosing from a taper tap, plug tap or bottoming tap. Match the tap size to thread the hole diameter. When you buy a tap with a drill bit they are size-matched for you, but they are most likely to be given in metric measurements. Use a conversion chart to match this with the inch fractions of your drill bit.
Finally lubricate the tap with tapping fluid, start the drill press, and lower the tap into the hole to be threaded. It should take only a few seconds to thread the hole and as long as you have set everything up correctly, you have a good chance for doing it correctly.