Metalworking is a time-honored industry that is indispensable to society as we know it. Techniques include welding, molding, casting and cutting. Within the discipline of metal cutting, you’ll encounter the fundamentals of drilling and tapping. Although these two actions often are used in tandem, it is critical to know the difference before you begin your journey with metal working tools.
Drilling: Creating a Smooth Hole
Drilling is one of the most common techniques for removing metal from a workpiece. By definition, it is the process of creating a smooth, cylindrical hole using a spinning implement to chip away the metal. It is common practice to drill a smaller pilot hole before drilling a large hole. There are many methods available for this task, such as using a mill machine or drill press.
The type of metal, thickness and size of the desired hole will help determine which methods and tools are the best fit. You will also need to choose which drill bits to apply to the task. The material metal removal rate (MMR) is a reliable metric for measuring tool efficiency. One of the most popular and versatile bits is the twist drill.
Tapping: Creating a Thread Into the Side of the Hole
If the hole is going to be used to hold a screw or a bolt, you will want to strengthen connectivity by cutting threads into the interior surface of the hole. This process is known as tapping and uses tools called taps. Tapping can also be applied to the interior surface of nuts.
It is critical to match the size and alignment of your tap drill to that of the drilled hole, especially when tapping by hand. There are formulas and charts available to help you make this decision, although it is more efficient to use a tap drill size calculator. Accuracy ensures the threading will be usable and that you do not break the tap drill or create cracks. You may also need to chamfer the edge of the hole.
Choosing Your Tools: Manual or CNC Machining
The choice between using a computer-operated CNC machine or a manual machine for drilling and tapping often comes down to budget, space and training. CNC machines operate using a computer with specialized software for improved accuracy, while manual machines can often be more affordable. Manual machines include:
- Drill presses
- Milling machines
- Handheld drills
Longevity is the goal when choosing tools for your machines. To keep them at their most productive throughout the years they may also need a little help. Many companies offer refurbishment services, such as Blue Box shipping, where you can mail in your tools to be reconditioned and brought back to life.
The instrumental processes of drilling and tapping are not to be taken lightly, as they lay the groundwork for all sorts of other manufacturing processes down the line. Understanding the difference is the first step to starting a successful career in metalworking. Put in the research before deciding which tools will work best for you.