1、Nitrided high speed steel is combined with titanium coated design, which is more sturdy and durable. 2、With two flute design, which provides smoother and faster drilling, high step design makes you feel the stop, never drill bigger in mistake. 3、Used with pistol drill or bench drill, water it to cool while working to prolong its life, the proper drilling speed is 250 to 400 rpm. 4、Suitable for these workpieces that hardness is lower than 28 degree and the thickness is beyond 5mm, such as thin steel board, wood, thin iron, aluminum alloy, insulation board, PVC plate, etc. 5、With high hardness and unique stepped structure, you can use one drill to open a aperture with different size.