Machine Elements & Parts

Thumb Head Screw – Complete Guide and Selection

Here we will talk about the thumb head screw applications. You can find detailed information about their features, and applications. And you can have detailed information about how to select them for different applications.

What is Thumb Head Screw?

Thumb head screw.
Image Source: Grainger.

A thumb head screw is a type of screw that has a very special head design. With this knurled head design, you can attach these screws to systems with your hand. The knurled system allows this attachment to the applications.

The most important advantage of the thumb head screw applications, you do not need to use an extra tool to attach them. You just need to squeeze the screw using your hand. Because of this, they are very useful for frequently disassembled systems. So, they are very useful for different kinds of applications.

But the most important disadvantage of the thumb head screw, the head section can be problematic. Because it is a very big section that stays on the structure. And in terms of design considerations, this can be a problematic issue. If we compare it with other screw applications, they have a very big protrusion.

Material of Thumb Head Screw Applications

In general, you can find two materials available for the head of the screw.

  • Stainless steel: If the head material of these screws is stainless steel, it has a very big structural strength in general. And you can apply very big squeezing power from the head of the screw.
  • Plastic: Also, plastic head material is also a very common application for screw applications. But the strength of the head and the attachment strength of the head material is not good as you expect from these applications.

Other Important Parameters for Thumb Head Screw Applications

There is also another important parameter that we need to consider about the thumb head screw applications in general.

  • Thread size: The thread size is a very important parameter that we need to consider. With the increasing thread size, the total number of turns required decreases.
  • Thread type: Also the type of the thread is very important. You need to select a type of thread that has the same as the other thread applications in the system. There are thread types such as UNC, UNF, and metric.
  • Thread spacing: The spacing of the thread defines the number of rotations that you need to attach the thread to the systems. So, there are thread spacing selections such as coarse, fine, and ultra-fine.
  • Length: The length of these screw applications is generally measured from the bottom side of the head.
  • Diameter: Select the diameter of the screw application that you need.
  • Head diameter: Select the total diameter of the thumb head screw.
  • Head height: Define the total height of the head that you want to attach to your systems.

These parameters are generally defined according to the metric and inch systems. So, you need to decide which standard sizing system you can to select the different applications.

Screw Head Shape

There are different head shapes are available that you can select for your application. These shapes are very important for different kinds of applications in general.

  • Round: This is the general shape of the thumb head screw applications.
  • Wing: Wşng screws are also a very common application. And holding power is much better for the wing screws. And also there are special tools that you can attach to the wing to rotate the fastener.
  • Multi lobe: There are lobes in the round shape of the screw head. This makes holding the head with a hand much easier.

There are thumb head screw applications that are available in the market that have fully threaded or partially threaded ways. We generally use the partially threaded ones for the workpieces that do not have threaded holes.

Also while you are selecting the thumb-to-screw attachment type, be sure that you care about selecting threaded stud types and other hand-press fit applications. Because press-fit applications tend to loosen over time. But the threaded stud ones have much higher resistance for squeezing.

Applications We Use Thumb Head Screw

There are various kinds of applications that we use these applications. They are very useful systems for these types of applications.

  • Electronic systems: In computers, printers, and other electronic devices, thumb head screws are very common because they are frequently removed by hand. Indoors and of electronic devices, the use of thumb head screw applications is very common.
  • Furniture: There are chairs and desks that we need to disassemble frequently. The use of the thumb head screw applications is very common in these systems.
  • Toys: In toys, the use of these screws is very common.
  • Industrial applications: In conveyors, clamping equipment, fastening, and securing applications. They are very useful in that operators can change the systems easilyç
  • Outdoor applications: Outdoor applications such as camping equipment, recreational vehicles, and other applications, use thumb head screw applications.


Like the advantages such as easy to attach, and easy to handle, there are other disadvantages of the thumb head screw applications that we need to consider.

  • Limited holding power and torque: It s because we are not using any tools, and the holding power of these applications is limited. We can only apply a specific level of stress.
  • Vandalism: The systems that depend on these applications are open to vandalism. Because people can open it with their hands without any tools. And this can be a problematic issue in terms of security.


So, they may be very basic systems but there are very important points that we need to consider about them. There are different materials are available for thumb head screw applications. You need to consider the general materials according to the system that you will use.

Also, you need to consider different kinds of parameters while you are selecting the materials. They are very useful for different kinds of applications.

If you are thinking about using them in such applications that we stated above, it will be a very good idea to consider their disadvantages of them.

If you have any questions or comments about the thumb head screw applications, please leave them below.

And also you can find other useful articles and posts about the screws on!

Bind Head Screws – Geometry and Explanation

Screw Shank – What is the Purpose of This?

Pan Head Wood Screw Applications and Features

Oval Head Screw Guide – Types and Applications

Uğur Uygun

Hello everyone, I am Uğur. I am a mechanical engineer who has experience in different R&D departments of HVAC companies. With my best friend, I decided to build this website to share out knowledge and experience. And also, I am interested in automotive. So, I am writing about automotive and automotive-related articles here. Sharing my knowledge and experiences on these topics is a very big pleasure for me. I am willing to answer all of the questions people have about these topics.

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