Quickly sharpen, hone, and maintain the edges and points of cutting tools with the Norton India AO Triangular Knife Blade File. The choice of clock and watch makers for their ability to quickly produce sharp, long-lasting edges and points, these files hold up over time while continuing to deliver a consistent finish with each use. Choose the coarse grit to restore worn edges fast, the medium grit for producing the average edge needed for most tools, and the fine grit for the sharpest edges.