25 PCS Straight Shank Twist Drill Bit Material:high speed steel. Standard:DIN338. Production technology:fully ground. Surface treatment(color):bright Specification:from DIA.1.0mm to DIA.13mm by 0.5mm. Packing details:metal box. We can manufacture drill bit from DIA.0.3mm to DIA.13mm,according to customer's requirement. For the surface treatment,we also can do as customer's needs.