ER Collets and Tool Holders - Tormach Tooling System

ER collets are used extensively in machining applications. In mill work, ER collets are used to hold end mills, drills, taps, and reamers. In lathe work, ER collets are also used to hold small diameter boring bars. ER collets are used for work holding of small diameter round parts in milling and grinding applications.

ER collets have a clamping range and can be collapsed to hold slightly smaller hold diameters than the indicated size. The clamping range for most ER collets is +0/-.039” (+0/-1 mm); for ER collets smaller than 7/64”, the clamping range is +0/-.015” (+0/-.5 mm). Tormach ER collets are made from hardened alloy spring steel and have run out of 0.0003” or less. Each ER collet is laser-marked with size. ER collets are available in inch and metric sizes, both individually and in sets.

ER collets are available in a number of sizes. The following table shows the range available for each ER collet size.

ER Collets Size Range (Inch) Size Range (mm)
ER16 Collets 3/64" - 3/8" 1mm-10mm
ER20 Collets 3/64" - 1/2" 1mm-13mm
ER32 Collets 3/64" - 3/4" 1mm-19mm
ER40 Collets 1/8" - 1" 3mm-26mm
ER Collet Sets

ER Collet Sets

ER collets come in a variety of sizes in both Metric and Standard intervals. To help make your collet selection a little simpler, Tormach provides an array of sets for ER16, ER20, ER32, and ER40 collets. All of the Tormach Collet Sets come with a wooden storage box to help keep things organized.

ER Collet Holders

Tormach provides an array of Tormach Tooling System (TTS) toolholders for ER collets. These allow you to utilize any size ER collet with the TTS system, and specialized versions provide the option of tension/compression tapping.

ER Collet Holders

ER Collet Accessories

Wrenches, components, tightening fixtures, and even organization – everything you might need to make ER collets work with your Tormach machines can be found here.



Manuals, Technical Documents, Datasheets, Service Bulletins, and Drawing are all available in our Support Documents and Drawings Library.

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TTS - ER Collets and Tool Holders Documents