How Do You Drill & Tap Threads Into Metal?
Whether you are tapping aluminum or steel, you must be careful and use the correct drill to the right depth to properly tap a hole in metal. By using ample tapping fluid and assuring that the tap is going in straight, you can tap a hole perfectly without damaging the part or the tap. Removing a broken tap can mean hours of extra work. Determine the appropriate drill bit for the tap size you are using. If you make the hole too narrow, the tap will break under pressure and if you make it too big, the thread will be too loose for any screws that you use after you are done tapping. The Machinists’ Handbook has all the tap and hole sizes available, so consult with the book for the correct diameter for the hole. Drill the hole to be tapped using a manual mill, drill press or CNC machine. It is important to look at the print and note the tapped hole’s depth. Tapping holes requires that the hole be deeper than the tap depth, so go about an extra 1/4″ so that the tap does not bottom out and bre
