What Are Collets? A Guide to Use & Cleaning

Collets can be an extremely flexible and efficient way to hold cutting tools — whether it’s drills, endmills, taps, threadmills, dovetail cutters, or any other round shank tool. What Are Collets? The collet is the connection between the tool holder and the cutting tool. It features a circular design with a number of open slots, allowing the collet to collapse and support the size of whichever tool you’re using. By placing a collet into the collet nut, inserting the tool and then tightening the completed collet nut assembly onto the toolholder, applied pressure creates a clamping force. The result is a cutting tool that’s securely gripped through pressure with minimal tool runout which can be used with max efficiency. Collet Maintenance Collets are a high precision component that require occasional maintenance to retain their accuracy. Below are some tips that will help you maintain collets:
  • Use a cloth to clean the collet and a small, brass brush to clear the inside (sometimes the broken ends of tools & other debris can become lodged within).
  • Spray new collets with WD40 and wipe them down with a cloth. This will remove a protective coating that’s placed on collets after they’re manufactured (something that can make it harder to grip tools).
  • Make sure the slots are clear of debris, as this can affect clamping force. Use something thin to do this, such as the end of a knife.
How Do You Know When It’s Time for a New Collet? Like any number of tools, collets may need replacing. A damaged collet can cause problems during the metalworking process. To determine if your collet is damaged beyond use, look for the following symptoms:
  • The collet has lost its shape (i.e. it no longer appears round)
  • Burn marks are visible on the collet
  • It appears the collet and nut were assembled incorrectly (check for a gouge on the nose of the collet).
  • The inside diameter is torn or no longer smooth.
If you need new collets, check out what we have in stock. For more questions about proper collet maintenance, contact the experts at RedLine Tools today.