OZ Collets

OZ collets are a manufacturer-specific toolholding system, similar in principle to ER but with a different taper profile and collet chuck design — the two aren't interchangeable, so check which system your toolholder uses before ordering a replacement collet. OZ chucks are common on older machining centres and some toolroom setups where the shorter OZ taper suits a more compact spindle nose.

We stock OZ12, OZ16, OZ25 and OZ32 in standard precision grade, covering the shank diameters typical of general milling and drilling work. As with any collet system, the collet has to match both the chuck it's fitted to and the shank diameter of the tool or workpiece being held — a collet from one size won't clamp a shank meant for another.

If you're specifying a new toolholder rather than replacing a collet in an existing one, ER collets are the more widely supported standard and easier to source spares for — see our collet buying guide for how the systems compare.