What is CNC Drilling: Definition, Working and Types

Updated: Jan. 24, 2024

Drill machines in CNC machining, there are not so many posts talking about this topic. making it easy to confuse their distinctive features. It may cause difficulty in choosing, preparing maintaining, and utilizing a drill.


This guide describes all the types of CNC drilling centers, provides their respective advantages, explains the types of products manufactured with the involvement of drilling, and discusses a dowel insertion machine programming method.

1. What is CNC Drilling?

CNC drilling is a machining process involving rotating cutting tools to produce round holes in a stationary workpiece. The purposes of drilling are aesthetic ones or for further accommodating of screws and bolts.


An example of a CNC drill can be seen in the image below.CNC Drilling Machine

Computer-based drilling is of particular usefulness for the mass production of components. Drilling functions can be implemented by advanced and versatile CNC centers incorporating numerous operations.

2. How Does CNC Drilling Work?

Without considering the preparation of a machine detailed below, the working process of a CNC drill can be described as the following. Spindles securing the chucks, drill bits, and other movable parts of a machine are activated by an operator through the control panel. Then, following the CAD/CAM file, a drill adjusts speed, fed rate, and the position of its spindles while cutting holes of appropriate depths and diameters.


After the machining is over, parts manufactured are checked for compliance, and adjustments are made, if necessary. Sometimes the manual change of tools in spindles is required if the pre-installed, in a tool changer, drill bits are not enough for all the types of holes needed in the design.


Related Post: Drilling Vs Boring Vs Reaming: What’s the Difference?

3. Advantages of CNC Drilling

Speaking about the respective advantages of CNC drilling, the referential models to compare with may be manual (traditional) drilling. The list below also incorporates the distinctive benefits of CNC drilling.


  • High accuracy and precision. CNC technology-based drills can reproduce the original designs with very tight margins.


  • Versatility. Drilling is considered a frequently needed operation, which can be applied to various materials from metal to foams. A variety of holes types is ensured with multiple drill bits existing.


  • Less percentage of sub-quality products. Correctly pre-adjusted CNC mills are less prone to errors, which leads to consistency and uniformity while producing large-scale orders.


  • It can be combined with other machining operations Drilling is often seen as a modification of routers or mills and can be incorporated in a single equipment unit simultaneously with other methods of material shaping.

4. Types of CNC Drilling Machines

Although drilling may not be considered machining, which would conceive many subtypes of CNC centers, there are several distinct ones intended for basic and specific purposes.


  • Upright drill press. It has a geared drive spindle head and is designed for machining heavy, large parts. It can be either CNC or manual type, requiring an operator to feed a workpiece. It is known for feeding a workpiece to a cutting tool instead of vice versa.


  • Radial arm drill press. This type of CNC drilling machine incorporates the basic mechanism of positioning a movable spindle over a stationary workpiece. The wheel head gives a cutting tool enough versatility to perform numerous operations on parts presented with most sizes and forms.


  • Gang drilling machine. This press has several work heads (avoid confusion with spindles, several of which may be present in one work head). Typically, those work heads are positioned over a worktable, where a part is fixed or mounted. It enables doing several successive operations simultaneously.


  • Multiple spindle drilling machine. It has several spindles connected to one work head, and all of them are fed to a workpiece simultaneously. Such machines are highly needed for producing components with a large number of holes located close to each other.


  • Micro drill press.It is the most accurate CNC drilling machine with small chucks. A micro drill press is useful for shaping macroscopic components.


  • Turret type drilling machine. This one has several work heads mounted on a turret. It enables quick changing of cutting tools and their positioning over a workpiece.

5. What Products Require CNC Drilling?

Concerning the types of products, CNC drilling comes in handy in crafting of which, the scope of application is the following:


  • Metal fabrication. Holes drilling in solid metal for automobile, aerospace, and other industries are the most frequent use of this machining. Some of such products may include turning wheel hubs, custom shafts, gear blanks, and more.


  • Wood manufacturing. Along with other machining operations, drilling is the frequent method of shaping wooden workpieces for furniture or other purposes.


  • Electronic components. Highly precise CNC drilling machines can shape computer parts of microscopic sizes at rapid production rates.


  • Electrical industry. Some electrical components intended to transfer power require drilling for their production.



The broad scope of application of CNC drilling makes machines incorporating such machining operations highly popular on the market.


6. How to Program a CNC Drilling Dowel Insertion Machine?

The distinctive feature of a CNC drilling & dowel insertion machine is that it not only makes holes but inserts in them hidden fastest known as dowel joints. Such constructing decisions enable the simple arrangement of furniture with basic instruments. An example of the CNC machine is shown in the image below.



From the perspective of programming, a CNC drilling & dowel insertion machine to be operated correctly should be prepared according to the same steps as any other machine.


Such stages are detailed further, along with some additional information enabling to deepen more into programming, particularly a CNC drilling & dowel insertion machine.

Computer-aided designing (CAD) software

It is necessary for creating a shape which is to be manufactured from a raw workpiece further. Besides the regular cuts, noises, holes, etc., dowel joints are additionally designed, so they suit ports in parts perfectly.


Computer-aided machining (CAM) software

Then, using means of G-code programming (read more), the created design is converted into a file that a CNC machine can read. Depending on the software installed in a center, distinct files for a part and dowel joints may be needed.


Control software

The operation of motor drives is ensured by signals from software utilizing a G-coded file. At this stage, the correct functioning of work heads, especially those holding dowel joints and spindles (and then the spare ones, so they do not interrupt machining), are checked.


Simulation software

This type of software is needed to revise a G-coded file and predict and eliminate errors that may arise while machining. Considering that CNC drilling & dowel insertion machines are known to be comparatively complex centers, this stage is vital to prevent manufacturing sub-quality products.


Being similar to CNC milling machine, CNC drilling & dowel insertion machines still have some significant differences requiring attention.

7. Final Word

CNC drilling machines fulfill the function of making holes of any depth and diameter in workpieces. There are many drill types, mostly intended for the convenience of the process and increasing production rates.


CNC drilling machines require pre-programming, as any other CNC center does. Some drills, such as drilling dowel insertion machines, may require complex preparation.

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