WeTeamUp Terms: “Collet”


What’s a “Collet”?

[kol-it] – Noun

The collet is the mechanism that holds the milling tool in the spindle during operation. It transmits the spindle’s power into the tool while keeping it precisely centered under milling loads. In dental milling machines, the collet opens and closes to allow for tool a changes during milling.  A properly functioning collet is essential to trouble free dental milling.

Interesting Details about Collets:

  • Collets require regular care.

A dirty or worn collet doesn’t work correctly. Make sure you’re aware of the proper maintenance recommendations for your milling machine’s collet. It’s common for them to be neglected. Sometimes the pressure of production makes it easy to forget to care for your machine’s collet. Keeping your collet clean, inspected, and in overall good health will help you avoid common milling issues like chipping and premature tool wear.

  • Collets wear out.

The life expectancy on a collet will vary from machine to machine, but they all eventually wear. A worn collet will suffer from reduced clamping force and will fail to hold the tool perfectly centered. A poorly performing collet will increase the amount of tool runout you have. Typically worn collets will be accompanied by heavy tool wear and lots of margin chipping.

  • Sub-par tools can reduce collet life.

Tools and collets must be precisely matched dimensionally. Lower quality tools can be under or oversized. Any inaccuracy in the roundness of the tool will be translated to the collet and cause excess wear. Keep this in mind when you’re calculating the cost of your tooling options.

  • Check your collet first.

If you’re experiencing milling issues, it’s likely caused by a dirty or used up collet. It’s always less costly to replace a collet than your spindle. It’s good practice to rule out collet issues first when trouble shooting milling issues. In fact, we recommend keeping brand a new one in stock for this purpose. Having the part on hand can help get you out of a bind quickly.

Thanks for reading! We hope this break down of the term “collet” has been of value. Stay tuned next week for another post like this!





Published by

Nick Alonge

Over 20 years of dental experience, specializing in digital training, workflows, and consultation. I'm happy to offer knowledge back to the industry.