For the best blend of cut rate and finish, choose the Norton India AO Diamond-Shaped Files, which are ideal for cleaning acute angles in dies and molds and stoning geometric chasers and sewing machine feeds. The aluminum oxide abrasive produces strong, long-lasting edges and uniform finishes without wearing down the shape of the file. Choose the coarse grit to quickly restore edges, the medium grit for general edge sharpening needs, and the fine grit for the sharpest edges.