Nicholson 12" Single-Cut Rectangular Mill Bastard File is a professional-grade tool designed for sharpening mill or circular saws and for draw filing and finishing metals. Its rectangular shape allows for smoothing and sharpening of straight surfaces, while the two square edges enable the creation of grooves with a fixed width. The file tapers slightly in width, improving access in slots. Made of high carbon steel with a width of 2.5", this file delivers durability and efficiency.