Bosch Impact Tough Titanium Nitride-Coated Drill Bit

Why I Reached for This Bit

I keep a handful of small-diameter bits in my kit for pilot holes, sheet-metal work, and light fabrication. The 1/16-inch Impact Tough TiN bit from Bosch has become a frequent pick when I need a tiny hole in metal without babysitting the bit after every few cuts. It sits in that sweet spot between everyday black oxide bits and more specialized cobalt or carbide options. If you work with mild steel, aluminum, or mixed materials and want something that holds an edge a little longer, this one makes a lot of sense.

Build and Coating: What You’re Getting

This is a conventional twist bit with a titanium nitride (TiN) coating. The gold finish isn’t just cosmetic; TiN increases surface hardness and reduces friction at the cutting edges. In practice, that means fewer micro-welds on the cutting lips, better chip flow at moderate speeds, and slower wear—provided you don’t overheat it.

At 1/16 inch diameter with a total length of 2 inches and about 1 inch of working length, it’s a compact bit. That shorter working length keeps it more rigid than jobber-length equivalents, which is helpful because small bits don’t tolerate side loading or wobble. There’s nothing exotic about the geometry here—it’s a straightforward twist drill profile suited for general metal drilling.

Test Setup and Materials

I used the bit across a few common shop and jobsite scenarios:
- Pilot holes in mild steel angle and flat bar
- Holes in 0.040–0.080 inch aluminum sheet
- Pre-drilling steel studs for fasteners
- Odds and ends in plastics and wood when I needed tiny, clean holes

I ran it in a cordless drill/driver and tried it in an impact driver as well, given its “Impact Tough” billing. I also used a drill press for a batch of repeat holes in mild steel to get a read on consistency and wear.

Drilling Metal: Control, Walk, and Hole Quality

In mild steel, the bit starts predictably with a light center punch. With bits this small, walking isn’t usually severe, but a quick punch still saves time and crooked holes. The TiN coating helps the cutting lips stay crisp by dulling more slowly than uncoated HSS, so the bit keeps biting instead of skating across the surface as it gets used.

Chip evacuation is what I expected for the size: fine, spiral chips that clear best if you “peck” the hole—advance, back out to clear chips, and continue. Running too hot and fast without chip clearing will glaze any small bit; the coating can’t fix that. Using a drop of cutting fluid on thicker steel noticeably improves the cut and extends edge life. On thin sheet, dry cutting at moderate speed with light feed was fine and produced minimal burring.

On aluminum, the bit was excellent. TiN shines here because the reduced friction resists chip welding, and I saw clean holes with very little clogging. A quick deburr was all that was needed.

Using an Impact Driver

Bosch positions this bit in a line designed to tolerate impact drivers. That’s useful on site when all you’ve got is a driver clipped to your belt. In practice, I could drill light-gauge steel studs and aluminum with an impact driver by feathering the trigger and keeping the tool square. The bit didn’t complain, but there are caveats.

• Small diameters don’t love impact pulses. If your driver can run smoothly at low RPM and you avoid hammering through the material, you’ll be fine for quick tasks.
• For thicker steel or precise drilling, a standard drill or drill press still gives better control and reduces the chance of snapping the bit.

I consider the impact compatibility a convenience feature, not a primary mode. It’s great in a pinch but not how I’d run a full day’s worth of holes in steel.

Durability and Wear

The reason to pick a TiN-coated bit is longer life versus bare HSS when you’re cutting common metals. Across a string of shop tasks—pilot holes for machine screws, small holes in brackets, a batch run in mild steel bar—the bit held its edge respectably. I didn’t see the telltale blueing at the tip, and it continued to pull a continuous chip rather than smearing metal.

Still, it’s a 1/16-inch bit. The most common failure mode is snapping from side load or catching on exit, not wearing out. The TiN coating helps the edges stay sharper, but it doesn’t make the bit less brittle. Treat it gently, clear chips, and let it cut at speed rather than forcing it. If you do sharpen it later, know that you’ll grind off the TiN at the cutting edges, losing the coating benefit. At this size, sharpening is finicky; I usually replace rather than sharpen.

Size and Length Considerations

With roughly 1 inch of working length, you’re set for sheet metal, thin bar stock, and pilot holes in fittings. If you need to reach deep into a part or through stacked material, look for a longer bit. The compact length is a plus for rigidity and accuracy but a limitation for deep work.

As with all small bits:
- Clamp your work. Even a slight shift can snap the bit.
- Use a center punch to start.
- Back off the trigger right before breakthrough to avoid hogging and catching.

Performance in Wood and Plastics

The bit’s clean cutting extends to non-ferrous and non-metal materials. In hardwoods and plastics, it leaves neat holes without burning when run at medium-to-high speed. The TiN coating doesn’t add much here compared to HSS, but it doesn’t hurt either. If you need very clean, tearout-free holes at this tiny size, use a backer board and avoid forcing the feed.

Practical Tips for Best Results

• Speed and feed: For small diameters in steel, higher RPM with light pressure works well. Listen for a consistent cutting sound and watch for continuous chips.
• Cooling: A dab of oil on thicker steel extends life. On thin sheet, dry is fine if you keep the speed reasonable.
• Chip clearing: Peck the hole. Don’t try to plow through in one go.
• Breakthrough: Ease up right before the bit exits. That’s the moment you’ll snap a small bit if you’re heavy-handed.
• Storage: If you rely on 1/16-inch bits, keep a couple spares. Even durable bits succumb to side load or a bad angle occasionally.

Value and Alternatives

This bit fills the gap between entry-level HSS and more aggressive alloys. If you routinely drill stainless or hardened steel, cobalt or carbide will serve you better. For general shop and site work in mild steel and aluminum, the TiN coating buys you a noticeable step up in longevity without jumping to specialty materials.

The availability in single- and multi-piece packs is a plus. For a size that’s easy to break, having multiples on hand is pragmatic. If you primarily need wood-only performance, any sharp HSS bit will do; the TiN advantage really shows up in metal.

What I’d Improve

I’d like clearer markings that survive pocket carry and multiple chuckings; small bits can be hard to ID at a glance. A bit more guidance from the manufacturer on recommended RPM ranges and an explicit note about best practices with impact drivers would also help users get the most from it.

Recommendation

I recommend this Impact Tough TiN bit for anyone who needs a durable, small-diameter option for frequent metal work—especially mild steel and aluminum—without stepping up to cobalt. It starts reliably with a punch, cuts cleanly, and holds an edge longer than uncoated HSS when used correctly. Impact-driver compatibility is a convenient bonus for quick tasks, but you’ll still get the best results with a drill or drill press.

If you respect the limitations of a 1/16-inch bit—short working length, delicate under side load—the combination of TiN coating, stable geometry, and the sturdy feel of the Impact Tough line make it a smart, everyday choice. For thin stock, pilot holes, and general mixed-material use, it’s earned a spot in my go-to index.