Authored by Nitesh

Mechanically attached elements frequently have threaded holes as essential components. Adding them is simple with CNC machines. After most of the part’s other features have been machined, threads are typically added. Making a mistake and throwing away a part can be very expensive, so using threaded holes is a good idea.

What Are Threaded Holes?

Using a die tool to drill the part, a threaded hole is a circular hole with an interior thread. Tapping is essential for creating internal threading when bolts and nuts cannot be used. Tapped holes are another name for threaded holes.

Types of Threaded Holes

There are two main types of hole threading, depending on the depth and opening of the hole. 

  • Blind Holes

Blind holes do not go all the way through the part you’re drilling. They can have a flat bottom if an end mill is used or a cone-shaped bottom if a conventional drill is used.

  • Through Holes

The workpiece is entirely pierced by the through hole. The result is a hole in the workpiece with two entrances, one on each side.

How To Create Threaded Holes?

Threading is a technique that could be made relatively simple with the correct equipment and understanding. The procedures listed below make it simple to cut internal threads into your parts:

  • Create A Cored Hole

The first step in creating a threaded hole is to use a twist drill to create a hole for a thread while keeping an eye on the required hole diameter. You should use the proper drill to reach the desired depth and diameter.

  • Chamfer The Hole

A drill bit is moved a little bit in the chuck during the chamfering operation until it reaches the hole’s edge. This procedure aids in bolt alignment and easy threading.

  • Drill To Straighten The Hole

Straightening the formed hole requires the use of a drill and a motor. Under this step, there are a few things to remember:

  1. Hole Size vs. Bolt Size

Before tapping, the hole size will be determined by the bolt size. Because tapping will enlarge the hole later, the bolt’s diameter is typically larger than the drilled hole.

  1. Going too deep

You must be careful with the hole depth if you don’t want to make a deep threaded hole. Because the type of tap you use will affect the depth of the hole, you should be careful while choosing it.

  • Tap the drilled hole

To ensure that a fastener is secure, tapping helps to produce internal threads in the hole. The tap bit must be rotated in a clockwise direction.

  1. Taper Tap

Because of its strength and cutting pressure, a taper tap is appropriate for working with hard materials.

  1. Plug Tap

For a large, deep-threaded hole, the plug tap is preferable. The internal threads are gradually chopped by a progressive cutting action used in its mechanism.

  1. Bottoming Tap

The beginning of a bottoming tap features one or two cutting teeth. When a hole needs to be dug exceedingly deeply, you employ them.

Considerations for Making A Successful Threaded Hole

The features of the material you’re working with, the characteristics of the hole, and various other factors are determined by the following factors:

  1. The hardness of the Substance
  2. Continuous use of standard thread sizes.
  3. Make Sure The Hole Is The Right Depth
  4. Pick appropriate machinery.
  5. Straight Surfaces
  6. The right position


When the screw cannot readily cut through the material, threading a hole is a connecting mechanism that enables you to cut threads in holes. The procedure can be difficult. As a result, this article covered the procedure and factors you should think about when making parts. the manufacturing expertise that can help you with any CNC machining requirements that you may have. 

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