Fast, accurate drilling: 135 split point tip starts on contact to prevent walking, while the parabolic flute clears chips fast. Reduced slipping: 3-Flat Secure-Grip shank holds the bit firmly in the drill chuck. Corrosion resistant: Black oxide coating provides lubricity and resists corrosion of the bit. Versatile: Reduced shank diameter for use in 1/2" chucks.