848 HSS Metal Twist Drill Bits, 4.1 x 44 mmHigh quality metal twist drill bits for precise drilling in metal. Made out of high speed steel (HSS). A finely-tuned material elasticity provides for a long service life. Very good concentricity. Tough viscous tempered bits ensure a particularly long service life. The hexagonal shaft ensures very good power transfer. Drive: hexagon, suitable for holders as per DIN ISO 1173-D 6.3.