Kango HSS Drill Bits are designed for an improved drilling performance into metal, plastic, and wood materials. This 25 Piece Set includes Drill Bits ranging from 1mm-13mm in size. Each drill bit has four cutting chamfers on the tip. These cutting chamfers provide maximum material contact, to deliver faster drill speeds and cleaner holes in metal.The 135° split point on the tip is designed to prevent the drill bit from wandering on startups. This feature provides more precision and contributes to faster startup speeds. The tapered shape of this Drill Bit results in a thicker core which provides additional strength to prevent bit breakage.The variable flute shape rapidly ejects chips and material to generate a faster, more efficient drilling action.