Bosch 5 Piece Impact Tough Black Oxide Drill Bit Set

A compact, impact-friendly bit set that actually earns a spot in my pouch

I’ve had this Bosch impact-rated black oxide set riding along in my drill pouch for a few months, and it’s turned into the handful of sizes I reach for when I’m already clipped into a 1/4-inch hex chuck. It’s a basic five-piece spread—3/32, 1/8, 5/32, 3/16, and 1/4 inch—but the choices make sense for everyday tasks. I used it across softwood framing, hardwood trim, plastics, and light-gauge steel with both an impact driver and a standard drill. The short version: it’s a convenient, quick-change set with better-than-expected accuracy on starts and decent life in wood and thin metals, provided you respect the limits of black oxide.

Design and build

Bosch gives these bits a few practical touches:
- 1/4-inch hex shanks that lock solidly into impact drivers and quick-change chucks
- A black oxide finish to reduce friction and help with heat management
- Extended flutes that move chips efficiently
- A “no-skate” tip geometry that bites early and reduces walking
- Laser-marked size labels that don’t rub off after a few trips in and out of holders

Out of the package, the grind quality looked consistent with no burrs at the cutting lips. Shanks were straight and seated true in several different chucks I tried. The black oxide finish isn’t glamorous, but it’s even and does what it’s supposed to do.

Starts and accuracy

The tip geometry is the standout. In wood and plastic, these bits started cleanly without a pilot dimple, even when I intentionally pushed the angle a bit to see if they’d walk. In thin sheet metal (aluminum, galvanized steel), a light hand and square alignment gave me controlled starts without a center punch. On smoother, harder stock—like polished mild steel or thin stainless—I still recommend a punch or at least a firm bracing to prevent wander, but the tips here clearly reduce the tap-dance you get from cheaper black oxide sets.

Hole roundness and size accuracy were good in wood and plastics. In mild steel, the 1/4-inch bit cut on size with controlled feed and lubricant. The smaller sizes are true enough for pilot holes and hardware clearance without reaming.

Chip evacuation and speed

The longer flutes help. In pine and fir, chips cleared fast, and I could keep the RPM up without scorching. In oak and maple, I used a steadier feed; the bits still pulled chips well and left clean walls. Plastics (PVC and polycarbonate) cut smoothly if I backed off speed to avoid melting. In sheet metal, a quick peck cycle—advance, back out to break chips, repeat—kept things cool and prevented snagging. The set isn’t aggressive to the point of grabbing, which makes them forgiving if you’re drilling awkwardly positioned holes with one hand on an impact driver.

Impact driver behavior

Impact-rated hex-shank bits aren’t just about surviving torque; they’re about not spinning in the chuck. These lock in positively and transfer torque without the tiny slips you sometimes feel with round-shank bits in 3-jaw chucks. With an impact driver, the 3/32 and 1/8 bits still require finesse—small-diameter bits will always be more vulnerable to snapping when the hammer action kicks in. Using the driver in drill mode (no impacts) or feathering the trigger on thin metal greatly reduces risk. The larger sizes handled light hammering in wood without complaint.

Runout through a hex interface is always a touch higher than a premium round-shank bit in a collet, but for general work the differences are negligible. If you need precision-drilled holes for press fits, you’ll likely reach for a dedicated twist bit in a drill anyway.

Materials and limits

Black oxide is a reasonable general-purpose choice, but it’s not a cure-all. My results:

• Softwood and hardwood: Excellent. Fast, cool cuts, clean exits with minimal tear-out when backed.
• Plastics: Very good. Keep RPM moderate and pressure light to avoid melting; the bits leave smooth holes.
• Light-gauge aluminum and mild steel: Good. Use cutting oil and moderate speed; peck to control heat.
• Thin stainless sheet: Possible but not ideal. I was able to get through a piece of thin 304 sheet with the 1/8 and 3/16 bits using oil and slow speed, but wear accelerated. For anything beyond very thin stainless or multiple holes, switch to cobalt or a nitride-coated high-speed steel bit to avoid work-hardening and premature dulling.

The set’s own specs list stainless as an application, and that’s true for light-gauge, careful work. Just know that black oxide isn’t the best match for heavier stainless jobs.

Durability and edge life

After a steady diet of wood and mixed plastics, the cutting lips still feel crisp. In mild steel, I noticed the 1/4-inch bit losing a bit of bite after a handful of holes without lubricant—using oil slowed that down markedly. The smaller bits held up fine for pilots in metal, again with sane speeds and lubrication. If you routinely drill steel plate or lots of stainless, you’ll want a cobalt set alongside this one.

Laser markings have held up better than paint-filled stamps on other budget sets I own. The hex flats show normal scuffing from quick-change collets but no rounding.

Ergonomics and day-to-day use

The hex shanks are the convenience play here. Swapping between driver bits and drill bits is instant, and there’s no chucking/un-chucking dance on a ladder. The five sizes cover the most common pilot and clearance needs for screws up to 1/4-inch lag predrills, cabinet installs, and light electrical/mechanical work. I do miss a 7/32 bit occasionally, but the spread hits the essentials.

One note: these arrived in simple carded packaging. There’s no dedicated case, so plan on a bit holder rail or organizer if you want to keep them together.

Value

For the price class, the Bosch set lands in a sweet spot. You’re getting better tip geometry and more consistent grind than the bargain-bin black oxide packs, plus the impact-rated hex convenience. They won’t outlast cobalt in metal, but they also don’t carry that price—or the brittleness that can come with cobalt on wood.

What I’d improve

• Add a couple more sizes, especially 7/32 and 9/64, to bridge common gaps
• Offer an option with a small, durable case or rail
• Clarify stainless guidance; these are fine for thin sheet with proper technique, but they’re not a heavy-metal solution

Who this set is for

• Tradespeople and DIYers who work primarily in wood and plastics and occasionally in light-gauge metal
• Anyone who favors an impact driver with a quick-change chuck for speed and convenience
• Installers and service techs who need reliable starts and decent edge life without babying bits on the job

If your week is filled with thicker steel or stainless, this is your secondary set—not your primary.

Recommendation

I recommend this Bosch impact-rated bit set for general-purpose drilling with an impact driver or drill in wood, plastics, and light-gauge metals. The hex shank convenience, reliable tip geometry, and solid chip evacuation make everyday tasks faster and cleaner, and the laser-marked sizes are a practical touch. Just set expectations appropriately: in thin stainless it’ll get you out of a pinch, but for repeated or thicker metal work you should pair it with cobalt or similar metal-focused bits. For most installs, shop projects, and maintenance tasks, this compact five-piece set earns its keep.