What Is a Collet Used For?

What Is a Collet Used For?

A collet is a cylindrical sleeve that is classified as a subtype of chuck. The sleeve is used to form a collar around a tool or device, with a pointed outer surface and a tube-shaped inner surface. Collets apply a powerful clamping force on the object they are holding when tightened, generally provided by the conical outer surface. 

Collet: Definition

Collets form a collar around a workpiece or tool. Generally manufactured from spring steel or other similar materials, they are usually made with a vertical kerf, a slit created by cutting a piece of material with a saw. Collets are used to hold a tool in a central position as it rotates. As the tool is inserted into the collet, the device expands and provides uniform pressure that holds the tool in place. However, if the collet stretches too far, it cannot secure the instrument properly and may lose shape. 

In general, the terms collet and chuck are used in contradistinction. Tools can be secured with either a chuck or a collet. In the context of this overview, chuck is used to refer to any chuck type other than a collet. 

General Collet Features

Collets have a limited range of motion when it comes to clamping. Many collets may be needed for projects that require clamping a given range of bits. Thus, the upfront investment to purchase these pieces is high, making them inappropriate for usage in electric drills and other tools with numerous components. However, the collet is often preferred over a traditional chuck because it can withstand harsh work environments and is suitable for repetitive tasks. Several features make collets ideal for a variety of applications: 

  • Quick clamping process
  • Precise centering
  • Reliable, strong clamping 
  • Resistance from being forced loose 

Collet Applications

As with any tooling mechanism, there are many types and sizes of collets, making them versatile enough for various industries that require clamping devices. They are commonly used in a variety of machining industries:

  • Woodworking: Collets are often found in drill presses, making them a natural fit for the woodworking industry. In drill presses and similar cutting devices, collets form a collar around router bits to keep cutting mechanisms in place. 
  • Metalworking: The applications for collets in the metalworking industry are numerous, as many devices require clamping capacities. Generally, traditional metalworking collets are used to secure round bars and tools. Other types of collets, including square and hexagonal, are used for specific projects. Metalworking applications also use e-collets, step collets, and soft collets to secure larger pieces in place during particular jobs. 
  • ER collets: These devices are often considered the best choice for manufacturers when it comes to clamping devices. An ER collet is a CNC tool used to hold various components used in mills. These devices consist of the main body and a threat end. The nut screws onto the main shaft. ER collets are available in ER-8 through ER-50 series, with each model number referring to the holder’s diameter size in millimeters.

Collets are also widely used in machine engines to form a collar for the inlet and exhaust valves and keep them under consistent pressure. As well, these devices are utilized in semiconductor projects and for many types of consumer crafts.  The automotive industry employs collets in various engine applications to keep internal mechanisms under constant pressure. 


Whether you are operating a drill press or a CNC mill, collets are likely used to keep it running. TM Smith Tool is a recognized leader in the tool-holding systems industry. We provide high-quality parts, including various sizes of collets, for clients based all over the U.S. 

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