Straight (tooth) files are made from alloy steel & have teeth which are undercut resulting in faster cutting with less effort. They may be used on all materials from aluminium to hardest steel without clogging. The undercut & generous radius at the root of the teeth enables the file to clear itself whilst in use. Millenicut files feature a straight tooth cut diagonally on the blade. Size. 12in. Half Round 9 Teeth per inch Tanged