Shop Half Round Files For Metal Drill America 4″ Flat Bastard File, DIC Series Pipe File The backs of all half round second cut files longer than 6 inches are double cut, the 4 and 6 inches files are single cut. The backs of all half round smooth files are single cut. The backs of all half round bastard files are double cut. Drill America 4 Half Round Bastard File Dic Series For Sale Tacoma Screw Products | 4" Bastard Half Round File Double Cut Metalworking File All 4, 6, 8 and 10 files are single cut. 12 bastard and second cut are double cut, 12 smooth is single cut and 14bastard is double cut The flat sides of all half files are double cut Rounded on one side, flat on the other. Stanley Hobby File Set, 22-316 Available in American pattern