Milwaukee® THUNDERBOLT® black oxide jobber length drill bits are designed for extreme durability and long life. The THUNDERBOLT® web features a thicker core than a standard drill bit, which provides ultimate strength and protects against side-load breakage. A specially designed parabolic flute form clears chips and debris fast to keep the bit cool. A precision start, 135 split point tip starts on contact to keep the bit from walking for fast accurate holes. Excellent for drilling on curved surfaces, requires less effort to drill and is highly recommended for use with portable drills.

Milwaukee® Thunderbolt® Secure-Grip™ Jobber Length Drill Bit, General Purpose, Imperial, 5/16 in Drill - Fraction, 0.3125 in Drill - Decimal Inch, 4-1/2 in Overall Length, 3-3/16 in Cutting Depth, Parabolic Flute, 3-3/16 in Flute Length, 3-Flat Shank, 135 deg Point, Split Point, Right Hand Cutting Direction, HSS Cutting Edge, HSS, Black Oxide, Applicable Materials: Metal, Plastic and Wood

• Extreme durability - thicker web provides greater strength and longer life
• Fast, accurate drilling - 135 deg split point tip starts on contact to prevent walking while the parabolic flute clears chips fast
• Versatile - reduced shank diameter for use in 3/8 in chucks
• Corrosion-resistant - black oxide coating provides lubricity and resists corrosion of the bit