Features:

100% Brand New and High Quality
Made from high quality HSS steel
Ideal for using to cut holes in a variety of materials including steel, brass, wood, plastic, etc.
Titanium coated to reduce mit and heat
Heat treated and highly polished. Drills perfectly round holes in steel, brass, plastic, wood etc.
3 sided shanks design in order to prevent slippage when in chuck
Two flute design drives faster, smoother and cleaner cuts each step is clearly labeled with the depth diameter in steps

Function: Deburring, Chamfering, Cutting or expanding holes
Supporting tools: Pistol drill, Hand drill, Charging drill, Bench drill. (Water injection cooling while working, it can effectively extend the service life of the drill bit, especially in the case of continuous drilling)
Rotating speed:
3-12 speed:260-400
4-12 speed:260-400
4-20 Speed:180-240

Attention:Because of the outer diameter of each step of the step drill is gradually expanded,then the corresponding cutting resistance and linear velocity will also be gradually increased.
Owing to the step drill is completely dependent on the inclined edge that is only with 1mm length,If the feed speed is too fast when drilling,it will be easily to be annealing caused by abrasion of the oblique edge.
Please give a downward force when drilling, do not press down too hard to avoid the edge wearing.

Suitable material: Workpieces with general hardness, such as wood, plastic, PVC plate, iron plate, plate thickness within 3MM. Please note that stainless steel and spring steel are not applicable. Not for quenching.  (Water injection cooling while working, it can effectively extend the service life of the drill bit, especially in the case of continuous drilling)

Length: 

3-12mm Length: Approx. 7.9cm/ 3.11"
4-12mm Length: Approx. 6.7cm/ 2.64"
4-20mm Length: Approx. 7.4cm/ 2.91"

The  Cutters Come in the Following Sizes:
3-12mm(3mm,4mm,5mm,6mm,7mm,8mm,9mm,10mm,11mm,12mm) 10 Steps
4-12mm: (4mm, 6mm, 8mm, 10mm, 12mm) 5 Steps
4-20mm:( 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm)9 Steps

Package included:

1 x Drill Bit  3-12mm
1 x Drill Bit  4-12mm
1 x Drill Bit  4-20mm
1x Bag(Option Option and Blue or Black Random Delivery)