Loading the collet into the spindle

Make sure you have followed all the steps in the collet maintenance section before loading a collet.


Load the collet into the nut first (1).

Then insert the nut and collet assembly into the spindle taper (2).

Never set the collet into the spindle taper first, and then screw on the nut. This would damage the eccentric washer in the nut.

ER16 collets (ISO 15488)



The collet will have a recessed ring around the outside.

This recess fits over an eccentric washer inside the collet nut. 

There is a mark on the bottom of the nut which indicates where the widest part of  the washer is.

Insert the collet into the nut at at an angle so the collet recess can sit over the widest part of the washer as shown:

Once the collet recess is over the widest part of the eccentric washer, straighten the collet. There will be an audible click, which means it is fully inserted.

If the collet is correctly inserted it will spin freely in the nut but it will not easily pull out.

OZ collets (ISO 10897)


OZ type collets do not have the eccentric washer. To insert an OZ collet into the nut simply push the collet into the nut until you hear a click.

Releasing a jammed OZ collet

The OZ is a budget solution, which as a consequence often jam in its receiving taper. If jammed, loosen the collet with a squared wooden or rubber mallet from behind with a light blow (do not use any hard tooling).

The arrow below indicates the direction of force.

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