Abstract: A device for securing teeth to a tooth adapter of an earth-moving machine includes a pin removably inserted through at least one first aperture on a tooth and one second aperture on a tooth adapter of a machine. The pin includes at least one expanding element adapted to reversibly switch from a retracted position to an expanded position by moving in a plane substantially perpendicular to the longitudinal axis (x-x) of the pin. The device further includes at least one retaining element associated with at least one of the first and second apertures, and provided with at least one seat for at least partially receiving the expanding element when the expanding element is in the expanded position.