Twist drill bit
Broca helicoidal
- Date
- 1861 · confidence medium
- Place
- East Bridgewater, Massachusetts, United States
- Credited to
- Stephen A. Morse
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
A drill bit with helical flutes that clear chips from the hole and admit coolant, and a sharpened conical tip. Morse made them by milling the grooves into the steel instead of twisting a bar, allowing mass production.
The twist drill is credited to Morse (1861), but there are earlier patents for twisted drills. Morse's milled version and his company (Morse Twist Drill and Machine Co., 1864) are the well-documented facts.
What it led to
- precise holes in metal in factories and workshops
- high-speed steel and carbide bits
- industrial pillar and portable drills