Milwaukee Thunderbolt® Silver & Deming drill bits are designed for performance in low to high tensile strength materials, stainless steel and cast iron. Thunderbolt® twist drill bits are made from premium industrial-grade steel with heavy-duty cutting surfaces that power through deep or shallow holes with lightning speed. A special flute geometry adds strength while providing increased chip ejection. Thunderbolt® twist drill bits have a heavy duty 135 degree split point for easy penetration and a 1/2 in. reduced shank with 3 milled flats which prevent slippage in a jawed chuck. One per package. Extreme durability: Thicker web provides greater strength and longer life.135 degree split point tip starts on contact to prevent walking.The parabolic flute clears chips fast.Black oxide coating provides lubricity and resists corrosion of the bit.Reduced shank diameter for use in 3/8 in. chucks.Corrosion resistant - Black oxide coating helps resist corrosion of the bitVersatile reduced shank diameter for use in 3/8 in. chucks3-Flat Secure-Grip shank holds the bit firmly in the drill chuck for reduced slipping11/16 in. diameter
