Civil Engineering Reference
In-Depth Information
Fig. 4.19. This is a Clarkson Autolock chuck with a set of imperial and metric collets
and an Autolock spanner. The collets with the plain ends are imperial collets, and the
collets with a groove around the collar (bottom left being an example) are metric col-
lets. I believe the threaded ring can be tightened against the end of the spindle to
make the whole assembly more rigid although I have never tried this.
ER collet holders
As mentioned earlier, the ER holder comes in various sizes. The smallest is
ER11 which takes collets from 0.5mm to 7mm. The largest collet size is the
ER40 range which goes from 2mm to 30mm.
The ER collet is a double angle collet which can be closed down by up to
1
⁄
2
mm (sometimes as much as 1mm) to tighten on smaller shanks than the
