collet
noun
col·let ˈkä-lət 
: a metal band, collar, ferrule, or flange: such as
a
: a casing or socket for holding a tool (such as a drill bit)
b
: a circle or flange in which a gem is set
Example Sentences
Recent Examples on the Web The work of tightening the collet, a fist-size ring, is now complete, said Cliff Lanham, senior vehicle operations manager for NASA’s Exploration Ground Systems Program. 
Ashley Strickland, CNN, 20 July 2022 The Floeting diamond stands alone, with no gems on either side of it to block light, and the diamond is specially cut to accommodate the metal collet. Carol Besler, Forbes, 7 Dec. 2021 The bracelets consist of 112 diamonds with a total weight of approximately 150-carats and are open back and set into silver collet settings with gold on the clasp—much of the design was indicative of the period with the exception of the open back. Beth Bernstein, Forbes, 8 Oct. 2021 Next, place an aluminum-oxide grinding stone into the rotary tool and tighten the collet nut. Joseph Truini, Popular Mechanics, 21 Jan. 2020 From the plastic collet of the needle came a bloody froth. oregonlive, 5 Oct. 2019
Ashley Strickland, CNN, 20 July 2022 The Floeting diamond stands alone, with no gems on either side of it to block light, and the diamond is specially cut to accommodate the metal collet. Carol Besler, Forbes, 7 Dec. 2021 The bracelets consist of 112 diamonds with a total weight of approximately 150-carats and are open back and set into silver collet settings with gold on the clasp—much of the design was indicative of the period with the exception of the open back. Beth Bernstein, Forbes, 8 Oct. 2021 Next, place an aluminum-oxide grinding stone into the rotary tool and tighten the collet nut. Joseph Truini, Popular Mechanics, 21 Jan. 2020 From the plastic collet of the needle came a bloody froth. oregonlive, 5 Oct. 2019 Word History
Etymology
Middle French, diminutive of col collar, from Latin collum neck — more at collar
First Known Use
1528, in the meaning defined above