1/4" Thunderbolt® Black Oxide Drill Bit (12 PK)

The Milwaukee 48-89-2832 is a 1/4" Thunderbolt® black oxide drill bit set (12-pack) built for general-purpose drilling in metal, wood, and plastic. It’s one of the most commonly used mid-size bits in Milwaukee’s Thunderbolt lineup.

Key Features

• 135° split point tip – starts on contact and prevents walking for clean, accurate holes
• Thunderbolt reinforced web – thicker core increases strength and reduces breakage under load
• Black oxide coating – reduces friction and resists corrosion
• Parabolic flute design – clears chips quickly to keep the bit cool
• 3-flat Secure-Grip shank – helps prevent slipping in the chuck

Specs

• Size: 1/4 in (0.25")
• Quantity: 12 bits per pack
• Material: High-speed steel (HSS)
• Finish: Black oxide
• Overall length: ~4 in (jobber length)
• Flute length: ~3-3/4 in
• Use: Metal, wood, PVC, plastics

Best Uses

• Drilling holes for 1/4" bolts and hardware
• General construction and framing
• Medium-duty metal drilling
• Woodworking and shop use
• Everyday jobsite drilling where strength matters

Bottom Line

The 48-89-2832 is a core “workhorse” size in the Thunderbolt lineup—bigger than pilot bits and commonly used for final hole sizing in construction and fabrication. It’s designed for durability, repeat use, and clean starts, not specialty tasks like deep-reach or oversized drilling.