Installation Manual

The Collet fi ts round the shank of the bit and slides into the tapered interior of the holder. Near
the bottom is a groove which fi ts into the clamping nut and at the bottom another taper which
matches the clamping nut. The slots cut through the collet allow the segments to be forced
inwards round the bit as it is tightened into the holder. There is obviously a limit to how much it
can be compressed meaning the hole through the collet must match the diameter of the shank
of the bit.
Nut
Not just a simple fl anged nut, the design of the interior is important.
At the base there is a bottom taper, this matches the taper angle of the bottom of the collet and
ensures as it is tightened the collet is compressed evenly.
Above this is a retaining ring, this is very deliberately made wider at one side than the other, it ’ s
not supposed to be concentric to the nut. This retaining ring fi ts into the groove of the collet.
This holds the collet into the nut and also when you wish to remove a bit it forces the collet down
out of the taper of the holder breaking any ʻ cold welding ’ which may have occurred and so
releases the clamping around the bit allowing it to be removed easily.
The simple reason that the retaining ring is o ff set within the nut is to allow a collet to be inserted
and removed.
Collet Sizes