DEWDAT 3-Piece set of universal spiral flute step drill bit, High-step two-flute design high-speed steel step cone drill bit is smoother and faster,

Nitrided high speed steel is combined with titanium coated design, which is more sturdy and durable With two flute design, which provides smoother and faster drilling, high step design makes you feel the stop, and will not get deeper by mistake 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 With high hardness and unique stepped structure, you can use one drill to open a aperture with different size