Bosch Titanium Nitride-Coated Metal Drill Bit Set

Why these Bosch titanium bits earned a spot in my metal drilling kit

I’m picky about drill bits for metal. Too many sets promise long life and clean holes, only to glaze over after a couple of hot cuts or skate across sheet stock. After putting the Bosch titanium set (specifically the TI14 kit) through a steady mix of shop tasks—brackets in mild steel, holes in aluminum plate, and a few cautious passes in stainless—I came away impressed with how consistently these bits start, cut, and hold up when used correctly.

Standout features in everyday use

• No-skate tip: The biggest quality-of-life upgrade here is the easy starting. On flat steel and aluminum, I didn’t need a pilot hole to keep the bit from walking. On curved or painted surfaces, I still like to use a center punch, but the “no-skate” tip noticeably reduces wander.
• Titanium nitride coating: The TiN finish does what it should—cuts feel smoother and heat buildup is slower than with uncoated HSS. If you keep the speed reasonable and use a dab of cutting fluid, you’ll get a lot of clean holes before edges dull.
• Three-flat shanks (3/16 inch and up): Larger bits grip well in the chuck and don’t slip under load. This matters more than you think if your drill’s chuck jaws are a little worn or you’re driving with a high-torque cordless.

Real-world performance on metal

• Mild steel (angle, channel, plate up to 1/4 inch): Using a 1/8 and 1/4 inch progression, I got clean, round holes with uninterrupted chips and minimal chatter. A slow-to-moderate drill speed and cutting oil kept temperatures in check. I could feel the coating doing its job—less squeal, smoother feed.
• Sheet metal (16–20 gauge): The no-skate tip is the hero here. I could start holes accurately without the bit skating across the surface. Deburring edges were modest, easy to clean up with a countersink or file.
• Aluminum (plate and extrusion): These bits move through aluminum quickly. Retracting to clear chips prevents clogging. I prefer a spritz of lubricant to keep aluminum from welding to the flutes; with that, the finish stayed crisp.
• Stainless (304, light-gauge and bar): Smaller diameters were fine when kept slow with steady pressure and plenty of fluid. Larger diameters cut, but you’ll notice the effort climbs quickly. For frequent stainless work, cobalt bits still have the edge. That’s not a knock on these—just the right tool for the right job.

Across all materials, starts were predictable and holes stayed true to size. I didn’t experience chuck slip with the larger three-flat shank bits, even when pushing a 3/8 inch hole through mild steel.

Durability and sharpening considerations

TiN coating extends life primarily by reducing friction and heat. That advantage is real, but it depends on the operator as much as the bit. Run them too fast without lubricant and you’ll cook the edge. Use the right speed and a drop of oil, and you’ll be rewarded with a surprisingly long service life.

A practical note: if you sharpen bits at home, regrinding will remove the coating at the cutting edge. The bit will still cut, but you lose some of the coating’s benefit at the business end. I don’t mind this on common sizes that see a lot of use—it’s part of normal maintenance—but it’s something to be aware of.

Set options and size coverage

Bosch offers several packs that cover the essential fractional sizes for general metalwork:

• TI14: 14-piece core set from 1/16 to 1/2 inch, with a useful duplicate 1/8 inch.
• TI21A: 21 pieces with smart duplicates of commonly used sizes like 1/16, 5/64, 1/8, 3/16, and 1/4. If you’re frequently drilling pilot holes or doing layout, those extras save time.
• TI29: 29-piece, full 1/16-to-1/2 inch progression in 1/64 increments. If you fit hardware precisely or tap holes often, the complete size ladder is worth it.

I tested the TI14 and dipped into the TI29 to compare less common sizes; performance is consistent across the range. The inclusion of three-flat shanks from 3/16 inch upward is appreciated in every kit.

Tip geometry and starting accuracy

Bosch’s “no-skate” tip behaves like a split-point variant in use—it bites early and resists walking. I could start holes cleanly on sheet metal and thin aluminum without a starter punch. On rough or curved pieces (pipe, round bar), I still recommend a center punch for best accuracy. If you’ve fought with standard 118-degree points on thin stock, this tip style is a tangible upgrade.

Drilling technique that gets the most from these bits

A good bit deserves good habits. Here’s what worked best for me:

• Speed: Slower for steel, moderate for aluminum. As a rule of thumb, keep a 1/4 inch bit under about 1,000 RPM for mild steel; drop lower for larger sizes or stainless. If you see blue chips or smell burned oil, you’re too fast.
• Pressure: Firm, steady feed. Let the edge cut; don’t lean until the drill bogs or the bit squeals.
• Lubrication: A drop of cutting oil on steel and stainless; a light lubricant or kerosene on aluminum if you have it. Wipe clean after to preserve the coating.
• Peck drilling: For deeper holes, especially in steel, lift periodically to clear chips and cool the tip.
• Workholding: Clamp the work. Accuracy and bit life both improve when the material doesn’t chatter.

Follow those basics and you’ll extend the life of any bit—these included.

What could be better

• Heavy stainless and hardened steels are not the sweet spot. That’s expected for TiN-coated HSS. If that’s your primary material, look at cobalt or carbide.
• After sharpening, coating benefits diminish at the cutting edge. That’s the nature of coated bits, but it’s worth planning for duplicates in the sizes you burn through most.
• The three-flat shank starts at 3/16 inch. I’d love a similar anti-slip feature on smaller sizes, though space constraints make that tough.

None of these are deal-breakers; they’re simply the boundaries of the category.

Who will appreciate this set

• DIYers and pros who work mostly in mild steel and aluminum and occasionally in stainless.
• Anyone who values clean starts on sheet stock without fussing with a pilot hole every time.
• Users with older or well-worn drill chucks—the three-flat shanks meaningfully reduce slip on the larger bits.
• Woodworkers or fabricators who need a reliable metal set in the toolbox without going to specialty cobalt for everything.

If you frequently tap threads, the TI29 set’s full progression is especially handy for matching drill sizes to tap charts.

Maintenance and storage notes

Wipe the bits after use, especially if you used lubricant, to keep the coating clean. Keep them segregated from masonry and wood bits to avoid grabbing the wrong tool and overheating the edge. If you snap a small diameter bit (it happens), replace it—don’t try to drill metal with a compromised flute.

Bottom line and recommendation

The Bosch titanium set strikes a smart balance of easy starts, secure chuck engagement, and durable cutting edges when used with proper technique. In mild steel and aluminum, they cut smoothly and predictably, and the no-skate tip saves real time on sheet work. They can handle occasional stainless within reason, but if you live in that material, cobalt remains the better long-term investment.

I recommend this set for general metal drilling in the shop or on the jobsite, especially the TI21A if you want duplicates of common sizes or the TI29 if you need the full size ladder. You’ll get reliable starts, reduced slipping in the chuck, and good bit life when paired with sensible speeds and a drop of cutting fluid. For the majority of metal drilling tasks most users face, these Bosch titanium bits are a dependable, good-value choice.