23/64" Thunderbolt® Black Oxide Drill Bit

The Milwaukee 48-89-2729 is a 23/64" Thunderbolt® black oxide drill bit, part of Milwaukee’s standard jobber-length general-purpose drill bit line used for wood, metal, and plastic drilling.

Key Features

• Black oxide coating – reduces friction and improves corrosion resistance
• 135° split point tip – starts on contact and helps prevent walking for accurate drilling
• Thunderbolt reinforced web – thicker core improves strength and reduces breakage under side load
• Parabolic flute design – clears chips quickly for cooler, faster drilling
• 3-flat Secure-Grip shank – reduces slipping in the drill chuck

Specs

• Size: 23/64 in (0.3594")
• Material: High-speed steel (HSS)
• Finish: Black oxide
• Length: ~4-7/8" jobber length
• Use: Metal, wood, PVC, plastic

Best Uses

• Larger bolt and anchor holes
• Structural metal fabrication
• Construction framing work
• General shop drilling where a 23/64" hole is needed

Bottom Line

The 48-89-2729 is a large standard drill bit size, not a specialty cobalt or impact bit. It’s just part of Milwaukee’s core “everyday metal/wood/plastic drilling” lineup.