Editing Collet (section)

==Other applications==

===Woodwork===
On a [[wood router]] (a hand-held or table-mounted power tool used in [[woodworking]]), the collet is what holds the bit in place. In the U.S. it is generally for {{convert|0.25|or|0.5|in}} bits, while in Europe bits are most commonly {{convert|6|,|8|or |12|mm|abbr=on}}. The collet nut is hexagonal on the outside so it can be tightened or loosened with a standard [[wrench]], and has threads on the inside so it can be screwed onto the motor [[arbor (tool)|arbor]].

===Craft hobbies===
Many users (hobbyists, graphic artists, architects, students, and others) may be familiar with collets as the part of an [[X-Acto]] or equivalent knife that holds the blade. Another common example is the collet that holds the bits of a [[Dremel]] or equivalent rotary tool.

===Semiconductor work===
In [[semiconductor]] industry, a [[die collet]] is used for picking a [[die (integrated circuit)|die]] up from a [[Wafer (electronics)|wafer]] after [[Semiconductor-die cutting|die cutting process]] has finished, and [[Wire bonding|bonding]] it into a package.
Some of them are made with rubber, and use vacuum for picking.

===Internal combustion engines===
[[File:Poppet valve red.jpg|thumb|upright|Valve, spring, retainer and split collet]]
Most internal combustion engines use a split collet to hold both the inlet and exhaust valves under constant valve spring pressure which returns the valves to their closed position when the camshaft lobes are not in contact with the top of the valves. The two collet halves have an internal raised rib which locate into a circular groove near the top of each valve stem, the outer side of the collet halves are a taper fit into the spring retainer (also known as a collar), this taper locks the retainer in place and the raised rib that sits in the circular groove on the valve stem also locks the collet halves in place to the valve stem. To remove the valves from a cylinder head a 'valve spring compressor' is used to compress the valve springs by exerting force on the spring retainer which allows the collets to be removed, when the compressor is removed, the retainer, spring and valve can then be removed from the cylinder head. It may be realized that the retainer does not budge when the valve spring compressor is used, this is due to a buildup of carbon which over time has locked the retainer and collets slightly. A slight sharp tap on the backside of the valve spring compressor above the valve stem should free the retainer allowing the springs to be compressed whilst retrieving the split collet. On reassembly it is difficult to keep the split collets in place whilst the compressor is released, by applying a small amount of grease to the internal side of the split collets will keep them in place on the valve stem whilst releasing the compressor, then as the spring retainer rises it locks the tapered split collets in place.

===Firearms===
[[File:Repetiergewehr mit Spreizhülsenverschluss zurückfedernd CC BY-SA 4.0 by Grasyl.svg|thumb|upright|Schematic of a (straight-pull) collet locked firearm operation]]
The [[Blaser R93]] (and related models) use a unique bolt locking system that employs an expanding collet. The collet has claw-like L-shaped segments that face outward from the axis of the barrel.<ref>{{cite web | url=https://patents.google.com/patent/US2297693A/en | title=Autoloading firearm }}</ref> The multiple claws give a large contact area to distribute load. As the [[breech (firearms)|breech]] is closed, the collet expands, extending the claws to engaging with an annular groove in the barrel just behind the chamber; locking the bolt closed.<ref>[https://www.youtube.com/watch?v=Yz8IbOXiH-k Blaser Straight Pull Rifles R93 R8 CISM LRS2], accessed 8 July 2021.</ref><ref>''[https://gundigest.com/rifles/hunting-rifles/the-all-un-american-straight-pull-bolt-action-rifle The All-Un-American Straight-Pull Bolt-Action Rifle]'', Gun Digest, accessed 2 June 2022.</ref> The [[Thompson submachine gun|Thompson .30-06 prototype]] used a collet locking operation.<ref>{{cite web | url=https://patents.google.com/patent/US1397698A/en | title=Gun }}</ref><ref>{{cite web | url=https://www.youtube.com/watch?v=bq8kvlZVlnM | title=Only Footage of the Springfield 30-06 Prototype | website=[[YouTube]] | date=7 October 2024 }}</ref>