Used for a variety of deburring, chamfering and radiusing applications, the Norton Hard Arkansas Stone Triangular File is best for cleaning tap threads, stoning cutting surfaces of milling cutters, lapping honing tools, dies and molds, and putting precision points on center punches. These files are also recommended for finish honing on countersinks. The Hard Arkansas natural novaculite delivers the sharpest edges and finest finishes while maintaining tolerances unequalled by any other abrasive file.