[Various sizes]: Professional HSS step drills can be used for precise drilling, with diameters ranging from 5 mm to 35 mm. You can machine large holes in one go without having to replace the drill bit and positioning holes.[High-quality material] HSS step drill is made of high-quality HSS steel and coated with titanium to reduce friction and heat. Classic high-speed steel, titanium surface coating, has recognized performance and durability when drilling holes in plastic, wood, aluminum, copper, stainless steel and many other types of sheet metal.[Easy to use]: The double-edged design makes drilling faster and smoother, and will not make you feel stagnant and resistance when using it. It has the best speed and accuracy.[ size] The size of drilling is clear and easy to make precise drilling. Pour water when working with step drills, which can effectively extend the service life.[Automatic impact]: When pressing the steps on the surface of the object, it will automatically produce a larger impact force, and the adjustable cover can adjust the impact force. The surface is very non-slip and can be accurately positioned without worrying about deviation.Material:HSS steelcolour:Silver+goldPackage Contents:1 x step drill1 x twist drill1 x center punchOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.