1. 4 SPIRAL FLUTES: The step drill bit is designed with 4 spiral flutes, the 4 cutting blades to ensure faster and smoother cutting, with high efficiency.
2. EXCELLENT STEEL: The step drill bit is made of M35 cobalt high speed steel, with a hardness of 89HRC, and can cut harder materials.
3. DRILLING DIAMETER: The bit is 12 steps design, with drilling diameter of 5mm, 7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, 21mm, 23mm, 25mm, 27mm.
4. APPLICABLE PLATE: This step bit is suitable for wood, plastic, stainless steel, aluminum, copper, and other metal plates, with strong practicality.
5. 1/4 INCH SHANK: This 4 flutes step drill bit is equipped with a standard 1/4 inch shank, can be easily installed on the tool, stable and reliable.

Specification:
Item Type: Step Drill Bit
Material: M35 Cobalt High Speed Steel
Drilling Diameter: 5mm, 7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, 21mm, 23mm, 25mm, 27mm
Shank Diameter: 1/4 Inch

packing list:
1 x Step Drill Bit
1 x Storage Box