Milwaukee Thunderbolt Black Oxide 21/64" Drill Bit 48-89-2821

ULTIMATE CORE STRENGTH FOR HIGH-DEMAND METAL AND WOOD DRILLING

Engineered to solve the most common failure point in jobsite drilling—bit breakage—the Thunderbolt® series utilizes a significantly thicker web core than standard jobber bits. This reinforced geometry provides the structural integrity needed to resist side-load snapping, especially when using high-torque portable drills in demanding positions. The parabolic flute design is a critical mechanical advantage, facilitating rapid chip evacuation to prevent heat buildup and extend the life of the black oxide coating. For professionals requiring precision, the 135-degree split point eliminates the need for center punching by biting into the material immediately, ensuring your holes stay on-center even on curved or polished surfaces.

• / Thunderbolt® Web Geometry: Reinforced thicker core provides superior strength and protects against breakage during heavy side-loading.
• / 135° Split Point Tip: Precision-ground tip starts on contact to prevent walking and delivers faster, more accurate holes in metal and plastic.
• / Parabolic Flute Design: Specialized flute shape clears chips and debris rapidly to maintain cooler operating temperatures.
• / 3-Flat Secure-Grip Shank: Machined flats on the shank prevent the bit from spinning in the chuck under high-torque applications.
• / Black Oxide Coating: Provides essential lubricity and corrosion resistance for long-term durability in harsh environments.

WHAT'S IN THE BOX

(1) 21/64" Thunderbolt® Black Oxide Drill Bit (48-89-2821)