Authentic Acoustic Flexible Core Guitar Strings Phosphor Bronze

Experience your acoustic guitar’s true voice with MARTIN Authentic Acoustic Flexible Core Guitar Strings Phosphor Bronze. This set blends a lighter-gauge version of our Superior Performance core wire with a heavier wrap wire to deliver a full, balanced tone and smoother playability from the very first strum.

• 92/8 phosphor bronze construction with bronzed-steel core wire and bronze wrap wire for bright projection, rich overtones, and durable sustain.
• Flexible core for easier bending and reduced finger fatigue, making these strings a practical choice for long practice sessions and expressive playing.
• Gauge options extra-light, custom light, light, and medium—carefully designed to unlock your guitar’s personality while fitting Martin instruments.
• Guitar compatibility we recommend using only our extra-light through medium gauges on Martin guitars to achieve optimal tension and response.
• Sound profile by gauge light-gauge strings deliver a lighter, shiny tone with airy volume, which suits smaller-bodied guitars and players seeking early bloom and clarity.

Who benefits most: beginners who want less finger fatigue and smoother chords, fingerstyle players who rely on precise note bending, and players seeking a brighter, balanced acoustic voice without sacrificing playability. These strings are crafted to fit your instrument and playing style, offering a tone that remains expressive across genres—from delicate fingerpicking to dynamic strumming.

With the Authentic Acoustic Flexible Core, Martin delivers a tone you can trust—crafted with care to help you set your creativity free. Whether you’re practicing at home, recording in the studio, or sharing a live performance, these phosphor-bronze strings give you the versatility, response, and authentic sparkle that define a Martin guitar.