Tuners, also known as machine heads, tuning pegs and tuning keys are mechanical devices used to set and hold the strings on a stringed instrument at a certain tension. Throughout the years a range of different styles have been used, from wooden friction-peg tuners on violins and other instruments, to makeshift eye bolts on cigar box guitars and other homemade instruments.
The term “tuners” can also be used to refer to analog or digital devices used to tune an instrument to exact pitch. See our entry on “digital tuner” for those.
The most commonly used style of tuners in the cigar box guitar world is the standard guitar-style tuners, either open-gear (acoustic guitar style) or close/sealed gear (electric guitar style). Some builders also use vertical ukulele/banjo style tuners, or even the more primitive zither pin style, which require a special wrench or key to turn.