CNC Drilling: Process, Advantages and Application

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CNC Drilling: Process, Advantages and Application

As various technologies in the world continue to evolve, the manufacturing industry is experiencing the same shifts. Drilling as a subset of CNC machining is one of the areas where the industry has enjoyed continuous development.

Specifically, there is now Computer Numerical Control (CNC) drilling, which is transforming the industry. In this article, we light into the intricacies of this process, and then outline its advantages and applications.

What is CNC Drilling?

CNC Drilling

CNC drilling is a widely used machining process where a drill bit rotates to produce round holes in a stationary workpiece. The stationary workpiece is held in place on a table as the rotating cutting tool works.

Manufacturers often create holes with a CNC drill when they plan to assemble parts using screws, bolts, and other components. CNC drilling is also being used to enhance the aesthetic element of products. Apart from metal, other materials that may be subjected to CNC drilling are plastic and wood.

How do CNC Drilling Process Work?

The CNC drilling process may be automatic, but there is still some level of manual input needed on the CNC machine. The operator follows a series of steps to actualize this process. Here are some basic steps of the CNC drilling process:

Step 1: Prepare the CAD file design

The engineers behind the drilling process will usually begin this process by generating the applicable computer-aided design (CAD) design. Examples of technical info that they are expected to put in the CAD software are tolerance and dimensions of the design.

The info will be instrumental for the operation of the CNC drilling in terms of tool path, speed of rotation, linear movement, etc.

When the CAD file is ready, the operator can translate the information for the CNC machine. With advancement, some CNC machines are capable of doing this translation.

Step 2: Import the CAD Model into CAM Software

The computer aided manufacturing (CAM) software automates the drilling operations. However, some software options have CAD and CAM software capabilities. In that case, they are referred to as CAD/CAM.

Through the CAM program, it is possible to create a CNC file in special formats (IGES and STEP). The typical format called G-code controls the drilling operations. The CNC drill will move according to the instructions given in the code.

Step 3: CNC Drilling Machine Setup

Here, you want to install the correct CNC drill and drill bits to the machine spindle or multiple spindles. Next up, the work piece is fixed on the machine and secured using fixtures and clamps ready for drilling. The operator adds the CNC program to the machine at the control unit. The program bears all the required information about the CNC drilling operation. These are feed rates, the location of the holes, and so forth.

Step 4: The Drilling Operation

With everything in its place, the drilling operation can be initiated. The CNC machine directs the drill bit to the points specified in the program and creates holes accurately and precisely.

The CNC programs, via the motors of the CNC machine, direct the different movements of the drill bit. Some of the variations of drilling that some advanced CNC machines can perform are tapping, countersinking, and counter-boring.

Types Of CNC Drilling Machines

There are different types of CNC drilling machines, categorized in terms of size, specific design, and other elements. Here is an overview of the most popular types:

Micro-drill Press

As the name suggests, micro-drill presses come with relatively small chucks. It is renowned for its accuracy which is much better than most of the other types. Use this CNC drilling machine for the best results in machining macroscopic parts.

Gang Drilling Machine

The most standout feature of the gang drilling machine is the multiple work heads. A single work head can carry several spindles. In most cases, the work heads will be overlooking a work table. Thanks to this setup, this type of CNC drilling machine can perform several drilling operations simultaneously.

Vertical CNC Drilling Machine

This version drills holes vertically. It is the preferred choice for heavier and sizeable workpieces.

Horizontal CNC Drilling Machine

The drilling machine drills holes in the horizontal direction. It is designed for smaller and lighter workpieces.

Multiple Spindle Drilling Machine

The head of the multiple spindle drilling machine carries several spindles. These spindles operate on the workpiece simultaneously using several rotating cutting tools. A CNC drilled component that has numerous closely located holes is best manufactured using this type of CNC drilling machine.

CNC Turret Drilling Machine

This type of drilling machine comes with a turret equipped with a few work heads. The main goal of this setup is to make the process of positioning and changing the cutting tools fast.

CNC Deep Hole Drilling Machine

When the ratio of the hole depth to the hole diameter is more than 10:1, the hole is termed a deep hole. There are special machines for drilling such holes called CNC deep hole drilling machines. They serve critical industries including aerospace, automotive, and oil & gas.

Advantages Of CNC Drilling

Here are some advantages of using CNC drilling:

Safer and Easier Process

Compared to traditional drilling options, CNC drilling is easy to use in the production of parts. Typically, the user only needs to specify a few details before starting the drilling process. You don’t even need to go into the details of how the machine works or how the programming part is done.

Even when some learning is necessary, the CNC drilling machine is straightforward. It also comes with advanced safety features and foolproof systems that enhance the safety of the user.

Higher Accuracy and Precision

CNC drilling is an excellent choice when one is looking for the highest quality parts and components. Over time, this technology has served manufacturers with precise parts. Medical and aerospace are good examples of industries that have continuously benefited from this advantage of CNC drilling.

Higher Cost Efficiency

Some industries use parts that have repeatable hole patterns. When the number of parts needed is huge, say, in the thousands, it is advantageous to use CNC drilling. The CNC drilling operation enhances production efficiency, as has been demonstrated in aerospace, automotive, and related industries.

Broader Versatility

Like in other CNC machining operations, there is a lot of versatility associated with the CNC drilling process. First, this technology allows for the use of a wide range of materials including wood, plastic, and metal. CNC drilling also can use several drill bits concurrently, thus it can produce diverse holes. When this machine is also capable of CNC milling, the capability is even higher.

Tips For Drilling a Precision Hole

Precision holes can be used to accommodate machine screws. A machine shop may use different technologies to drill precision holes. However, CNC drilling is among the most preferred machining processes for this task.

Consider the following tips when drilling a precision hole to avoid machining issues such as heat generation and chip clogging:

  • Use spindle coolant for deeper precision holes

  • Use pecking cycles in CNC drilling work

  • Consider the geometry of the drill- Does it help in chip evacuation?

  • Use a spot drill before the twist drills

  • Perform a reaming operation to achieve even higher accuracy of the precision holes

CNC Drilling Vs. Thread Tapping: What's The Difference?

The goal of computer controlled drilling is to form a round hole in the material or work piece. It is a fundamental procedure that could be followed by others. One such procedure is thread tapping.

Tapping forms threads in an already drilled hole. Depending on the complexity required, thread tapping can be either manual or CNC machine-based.

It is also noteworthy that while machinists typically use twist drills in CNC drilling, the tool of choice in thread tapping is a tap drill bit.

The goal of computer controlled drilling is to form a round hole in the material or work piece. It is a fundamental procedure that could be followed by others. One such procedure is thread tapping.

Tapping forms threads in an already drilled hole. Depending on the complexity required, thread tapping can be either manual or CNC machine-based.

It is also noteworthy that while machinists typically use twist drills in CNC drilling, the tool of choice in thread tapping is a tap drill bit.

Applications Of CNC Drilling

CNC drilling is so instrumental that virtually every industry uses the technology at one stage or the other. As the demand for advanced drilling machines increases, we are set to see more applications of CNC milling and drilling. Below are some of the most common applications:

Manufacturing Computer Parts

A lot of parts assembly takes place in computer factories. Various parts and components must be assembled before the computer can come to life. The CNC drilling process is necessary for assembly purposes.

Sheet Metal Works

The construction, automotive, aircraft, and many other industries use a lot of sheet metal. Holes are often required on the sheet metal for assembly and other purposes. Drilling is one of the main secondary processes that the sheet metal undergoes to achieve the final product.

CNC Machining for Woodworking

With its precision and reliability in repeatable jobs, CNC drilling is an integral part of woodworking applications. Wood product manufacturers use this technology to enhance the aesthetics of their products.

Beyond that CNC drilling for the wood industry offers high tolerance and precision of processes. The versatility of CNC drilling machines is also a significant asset to this industry.

Plastic Industry

The versatility and reliability of CNC drilling technology have seen it find relevance in the plastics industry. It is particularly a popular practice in prototype manufacturing.

Nylon, acrylic, Acrylonitrile Butadiene Styrene (ABS), and high-density polyethylene (HDPE) are all popular types of plastics that undergo CNC drilling.


The precision, versatility, cost-effectiveness, and all the other attributes of CNC machining operations are attractive to many manufacturing firms and users. An interest in understanding the basics of the CNC drilling process is understandably out there.

We believe that this guide on CNC drilling has been insightful to you. With the knowledge of the parts of the CNC drilling machine, your confidence level in tackling CNC machining projects is higher.

For all your CNC machining service needs, Aria Manufacturing is ready to offer a helping hand. Our blend of expertise and advanced CNC drilling machinery is unlike any other. Call our representative today and embark on a journey of reliable and superior quality CNC drilling services.


Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.