ER Collet Sizes

ER collets have a wide clamping range and high accuracy. While they are designed for tool holding, they work great for work holding in small lathes. With a full set of ER collets you can hold any diameter that is in the clamping range of the set.

There are several types of collets that look like ER collets. If your collet looks like an ER collet, but does not match one of the sizes shown above, it is a different type of collet and not an ER collet.

Chris' Tips With all ER collet chucks, the collet must be snapped into the nut before placing it into the chuck. There is an eccentric ring inside the nut that engages the groove in the collet. That is what makes them self-ejecting. Tilt the collet again to remove it from the nut.

The table below shows the available sizes of ER collets. Click the collet size at the top of the column (ER-32, for example) to go to the page that lists all the collets in that size range. This makes ordering several collets in the same size range simple.