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 10in Flat 9 Teeth per inch 2 Milled Edges Tanged