It is critical to properly assemble the collet and collet nut to avoid damage to the collet and make the most accurate and rigid assembly possible. The extraction groove of the collet must be properly seated to the extraction ring of the collet nut.
First, angle the collet so the extraction groove seats with the eccentric extraction ring in the collet nut as shown below.
Next, while holding the collet and nut together, place the assembly in the tool holder and begin tightening the nut. If the collet extraction groove is not properly seated to the collet nut extraction ring, the collet will appear seated below the face of the nut. This typically occurs when the collet is placed in the collet pocket of the tool holder and then the nut is threaded on the tool holder. In a correct assembly, the collet will seat at the face of the collet nut. The image below shows a correct assembly on the left and an incorrect assembly on the right.
DO NOT tighten the collet nut if the collet appears seated below the face of the nut as this will create galling on the 30Â° face of the collet. Galling appear as grooves or lines in the lead face of the collet.
Galling on the lead face of the collet can result in reduced clamping pressure on the cutting tool shank that may lead to the cutting tool slipping while cutting, or even tool breakage.
When trying to ensure the most rigid and accurate collet chuck assembly, donâ€t take chances. When in doubt, throw it out!
Remember, the collet is designed to wear out and is the least expensive component in a collet chuck system.