Fret (musical instrument component)

Construction and physical characteristics

Modern frets are typically made from fretwire, a metal rod with a rounded top and a tapered tang that is pressed or hammered into slots cut across the fingerboard. Typical metals include nickel-silver alloy and stainless steel; brass and other alloys are also used. The visible portion is called the crown, whose height and width vary between "jumbo", "medium" and "vintage" profiles. The fingerboard itself may be flat or radiused, which affects how frets are crowned and leveled.

How frets determine pitch

Each fret marks a raised contact point that shortens the string's effective vibrating length when pressed, producing a higher pitch. In most Western instruments the frets are spaced so that each successive fret raises pitch by one semitone in equal temperament. Roughly, this spacing is calculated so that the vibrating length is multiplied by the 12th root of 2 for each fret step; the twelfth fret therefore produces the octave, where the vibrating length is half of the open string.

Varieties and historical forms

Historically, many fretted instruments used movable tied frets made of gut or cord; lute and some folk instruments still employ these. Modern innovations include scalloped fingerboards (where wood between frets is carved away), fanned or multiscale frets (unequal spacing to suit different string tensions) and partial or microtonal fret systems for nonstandard scales. Fixed metal frets remain the dominant form for contemporary guitars and related instruments.

Function in performance and instrument setup

Frets make precise pitch placement repeatable and allow techniques such as bending and vibrato. They also interact with setup and intonation: bridge compensation and nut placement are adjusted so fretted notes are in tune across the neck. Low action or uneven frets can cause buzzing; worn or flattened frets change tone and may require dressing (leveling and re-crowning) or refretting.

Maintenance, durability and tonal effects

• Wear: Steel strings gradually wear fret crowns, creating grooves that can cause intonation problems.
• Repair: Routine maintenance includes leveling, re-crowning and polishing; severe wear typically leads to refretting the fingerboard.
• Tonal and playability differences: Fret size and material influence sustain, feel and the ease of bending strings—larger frets can enable less contact with the fingerboard, while small frets suit classical padding techniques.

Understanding frets helps players choose instruments and setups that suit their technique and musical style. For technical details about fret spacing formulas, installation and common repair practices, consult specialized luthier resources or guides devoted to the particular instrument family.