Bridge pins are used on some musical instruments to locate the string precisely in the horizontal plane, and in the case of harpsichords to affect the sustain of the strings. They are usually made of steel in modern pianos, of brass in harpsichords, and bone or synthetics on acoustic guitars. Electric guitars do not usually have bridge pins as, in guitars, they are used to transfer the sound from the strings into the hollow body of the instrument as well as holding the strings in place.
In pianos the pins are set precisely in line with the edges of the notches of the bridge. The precise and firm setting of the pins is a critical element of the piano's quality. Loose or inaccurate pinning commonly produces false beats and tonal irregularities.
In harpsichords there tends to be a significant distance instead. This enables control of sustain and tone in harpsichord design (as per external link).
Bridge pin may also refer to: