The Milwaukee 48-89-2321 3/8 in. Thunderbolt Cobalt drill bits are designed for extreme durability and long life in specialty applications. 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-degree 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.
- Longer life: titanium coating reduces heat build-up for up to 3x longer life
- Extreme durability: thicker web provides greater strength
- Fast, accurate drilling: 135-degree split point tip starts on contact to prevent walking, while the parabolic flute clears chips fast
- Extreme durability: designed for high performance with stainless steel, high alloy steel and cast iron