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Tag Archive: collets and tool holders

  1. Collets & Tool Holders Maintenance

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    Collets and Torque Wrenches

    Collets & Torque Wrenches

    One of the most critical and most over-looked parts of the CNC router is collet and tool holder maintenance issues

    Collets and tool holders are critical parts of any CNC; they should be thoroughly cleaned and inspected during every tool change. Collets are inexpensive and expendable, especially compared to the cost of the tooling that relies on its accuracy.

    Edge of Arlington carries Techniks collets and holders and parts. Guaranteed accurate.

    Collets are made out of spring steel and should be replaced at least every six months of daily use (400-600 hours of run time), or when there is any sign of wear or damage.

    Tools should be tightened with the aid of a torque wrench. Over-tightening can cause distortion and runout, leading to tool wear, breakage, and finish degradation. Under-tightening can lead to bit slippage and twisting in the collet. Torque wrenches should only be used to tighten; using a torque wrench to loosen a nut can lead to miscalibration.

    When using full grip collets, whenever possible the tools should be chucked to fill 80% of the depth of the collet. Fillers are available to prevent collet collapse in the event the 80% rule cannot be maintained. Full grip collets have slits running from the top and bottom.

    Never chuck up on the cutting edge of the tool but always just below the fade of the flute.

    The tool holder is also subject to wear and should be inspected regularly for wear and damage. 

    Spindle wipers for collets

    Techniks Spindle Wipers

    Collet brushes are available for cleaning. Clean using a nylon or brass bristle brush only. Use alcohol after cleaning to ensure there are no chemical residues remaining.

    Spindle wipers are available for cleaning the spindle where the tool holder mounts. Real lambskin provides the best cleaning.

    Recommended torque is based on the style of collet used in the tool holder. An HSK tool holder for example is available with several collet options. Torque has been calculated based on the unique properties of each collet style.

    While changing the bit, it is important to use a set-up fixture or similar device to hold the tool holder safely. Damage to the tool, holder, or operator can occur if the holder is dropped or clamped improperly.

    Remember! Over-tightening can distort collets, causing runout problems and premature failure of the collet, tool holder, and cutting tool. Improperly tightened tool holders are a safety hazard. Always use a tightening stand and torque wrench to tighten collet nuts and pull studs.

    Cutting tools last longer when you … Torque it right!

    If you have a question, feel free to ask us in the comment area, or contact us and we’ll be happy to assist you. As well, we look forward to your comments! Thank you for reading.


    For more, refer to our CNC Manual. 

    To peruse our online catalog or to place an order, visit or call us at 817-461-7171.

    For more informative EOASAW blog posts, visit our main Blog Page.