Milwaukee Thunderbolt Black Oxide Drill Bits: Built for Side-Load Abuse

Milwaukee’s Thunderbolt Black Oxide drill bits solve the biggest problem with standard bits — breaking under side-load pressure. The heavy-duty thicker core (web) provides increased strength and protection against the lateral forces that snap lesser bits. This 29-piece set covers everything from 1/16” to 1/2” in 1/64” increments, giving contractors the right size for every hole.

Skip these if you’re drilling stainless steel or hardened materials. While Thunderbolt Black Oxide bits excel at general purpose drilling and mild steel, Cobalt bits handle the hard stuff better — though they’re more brittle and cost more. For everyday jobsite abuse in wood, engineered lumber, mild steel, and plastics, Thunderbolt bits deliver.

The Engineering That Matters

The Thunderbolt Web design isn’t marketing fluff. That thicker core prevents the sideways flex that causes catastrophic bit failure when your drill catches or binds. Paired with parabolic flutes — extra-wide channels that clear chips faster — these bits run cooler and last longer than standard twist bits.

The 135° split point tip cuts on contact without walking. That’s the difference between drilling where you marked and chasing a bit across the workpiece. Every contractor has fought a standard 118° bit that wants to wander. The split point stays put.

Sizes 3/16” and larger get Milwaukee’s 3-Flat Secure-Grip shank. Those three machined flats lock into your chuck and won’t spin under high torque. Smaller sizes use round shanks — not ideal, but the physics of tiny bits limits what’s possible.

What’s Actually in the Box

Specification	Value
Total pieces	29
Size range	1/16” to 1/2” (by 64ths)
Material	High Speed Steel (HSS)
Coating	Black Oxide (heat treated)
Weight	2.975 lbs
Point angle	135° Split Point
Shank design	3-Flat on 3/16” and up; round on smaller

The included PACKOUT-compatible case deserves mention. Milwaukee designed it to work with their modular storage system, and the custom cutouts keep each bit organized. Some users report issues with case latches, but the modular design gets praise from those who’ve integrated it into their storage setup.

Real-World Performance

Black oxide isn’t just for looks. The coating provides lubrication and resists corrosion — both critical for Montana’s temperature swings and humidity variations. Unlike titanium-coated bits where performance drops once the coating wears, black oxide maintains its properties through the material’s bulk.

For metal drilling, use cutting oil. It extends bit life and improves hole quality. When mounting larger bits with the 3-flat shank, align those flats with your chuck jaws for maximum grip. Basic advice, but skipping these steps turns good bits into scrap metal.

Customer reviews paint a mixed picture — 4 five-star reviews praise the strength and case design, while 4 one-star reviews cite bits snapping under excessive stress. That’s actually typical for HSS bits pushed beyond their limits. These aren’t miracle workers — side-load protection doesn’t mean unbreakable.

Frequently Asked Questions

Are these bits worth the premium over hardware store brands? For contractors drilling dozens of holes daily, yes. The Thunderbolt Web and parabolic flutes deliver measurable improvements in durability and chip clearing. Weekend warriors might not notice the difference.

What’s the warranty situation? Milwaukee considers drill bits consumable accessories with no standard warranty, though they’ll replace manufacturing defects found at purchase. Standard practice for drill bits industry-wide.

Can these handle stainless steel? Not well. Thunderbolt Black Oxide bits target mild steel, wood, and plastics. For stainless or hardened steel, invest in cobalt bits.

Why do smaller bits have round shanks? The 3-Flat Secure-Grip shank appears on 3/16” and larger bits only. Physics limits how much material you can remove from tiny bits without compromising strength.

Do these work with impact drivers? These bits work with standard corded and cordless drills with 3/8” or 1/2” chucks. They’re not rated for impact drivers — use proper impact-rated bits for that application.