3Pcs/Set 3-12Mm 4-12Mm 4-20Mm Hss Straight Groove Step Drill Bit Coated Wood Metal Hole Cutter Core Drilling Tools Set

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)

Package include:
Type1: 3-12 4-12 4-20 bag
1 x Drill Bit 3-12mm
1 x Drill Bit 4-12mm
1 x Drill Bit 4-20mm
1 x BagBag color black blue random

Type2:3-12 4-12 4-20
1 x Drill Bit 3-12mm
1 x Drill Bit 4-12mm
1 x Drill Bit 4-20mm

Type3:4-12
1 x Drill Bit 4-12mm

Type4:4-20
1 x Drill Bit 4-20mm

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)