3M™ 420 Lead Foil Tape 3M™ 3M™ 420 Lead Foil Tape is an adhesive tape made of lead foil, designed for industrial applications requiring high conformability, effective sealing, and reliable protection. Its malleable construction and strong adhesive allow it to conform easily to irregular surfaces, providing a durable barrier against moisture, vibration, and certain types of radiation. Typical uses include joint sealing, insulation, sound and vibration damping, and specialized applications in industrial equipment and building systems. Learn more