Drilling into metal demands a bit that bites immediately and holds its edge through repeated passes against hardened surfaces. A dull tip or a wandering 118-degree point turns a five-second operation into a frustrating fight against work-hardening and broken shanks. The gap between a clean through-hole and a ruined workpiece is almost always determined by the drill bit’s material, coating, and point geometry.
I’m Mo Maruf — the founder and writer behind The Tools Trunk. I analyze thousands of product reviews and spec sheets each year to isolate the material science and design choices that separate genuinely capable metal-drilling bits from the disposable sets that burn out on the first sheet of stainless.
Whether you are punching through thin-gauge steel or thick alloy plate, the best drill bits for metal must combine a high-temperature alloy base, a heat-dissipating coating, and a self-centering 135-degree split point to deliver consistent results without excessive pressure.
How To Choose The Best Drill Bits For Metal
Five factors define whether a bit cuts cleanly through steel or fails within the first few holes. Ignore the packaging claims and focus on the alloy, the point angle, the coating chemistry, the web thickness, and the shank design.
Material Alloy: M2 HSS versus M35 Cobalt
Standard high-speed steel (HSS) bits work fine for soft metals like aluminum and brass, but they soften quickly against stainless steel or hardened alloys. M2 HSS adds tungsten and molybdenum for improved toughness. M35 cobalt steel introduces 5% cobalt, which raises the red-hardness threshold significantly. If your work involves stainless, alloy steel, or repetitive production drilling, the cobalt variant maintains its cutting edge at higher temperatures without annealing.
Point Geometry: Why 135 Degrees Wins
The included angle at the tip dictates how the bit interacts with metal. A 118-degree point walks aggressively on curved or hardened surfaces, requiring a center punch for every hole. A 135-degree split point self-centers, reduces downward pressure, and chips through the work-hardened layer. This geometry is non-negotiable for any serious metal-drilling task.
Coating Chemistry: TiN versus TiAlN
Titanium nitride (TiN) adds lubricity and wears longer than uncoated bits, but it degrades above 600°C. Titanium aluminum nitride (TiAlN) forms a heat-resistant ceramic layer that stays stable up to 900°C, making it the right choice for stainless and high-alloy steels. The coating is useless if the base alloy cannot handle the heat, so always pair TiAlN with cobalt or premium HSS.
Shank Design and Web Thickness
Round shanks can spin in the chuck under high torque, especially with impact drivers. Hex shanks lock positively and eliminate that slippage. The web is the central spine of the flute; a tapered web thickened toward the shank resists torsional breakage during deep plunges into hard metal. Bits with thin webs snap first when lateral pressure is applied.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| OSTTE M35 Cobalt 14-Piece | Cobalt / TiAlN | Stainless & hardened steel | TiAlN coating, 89 HRC hardness | Amazon |
| DEWALT DW1361 21-Piece | TiN / Pilot Point | General metal & wood | Pilot point tip, self-starting | Amazon |
| HIGHFIRE Hex Shank 22-Piece | Hex Shank / HSS | Impact driver metal drilling | 1/4″ hex shank, tapered web | Amazon |
| Drill Hulk Hex Shank 6-Piece | TiN / Hex Shank | Quick-change metal drilling | M2 HSS, 135° split point | Amazon |
| PLATINUMEDGE 99-Piece Metric | HSS / TiN | Budget variety & small sizes | 99 bits, 1.5 mm to 10 mm | Amazon |
In‑Depth Reviews
1. OSTTE M35 Cobalt 14-Piece Drill Bit Set
This set uses M35 cobalt steel with 5% cobalt content, which resists annealing at the elevated temperatures generated when drilling stainless steel and hardened alloys. The TiAlN nano-coating pushes surface hardness to 89 HRC and creates an oxide layer that dissipates heat away from the cutting edge, directly reducing edge breakdown during extended use. Each bit undergoes a full grind process, and the 135-degree split point eliminates the need for a center punch on most flat surfaces.
The fourteen bits range from 1/16-inch up to 1/2-inch, with the larger diameters featuring three-flat shanks that lock positively in the chuck without spinning. User feedback consistently highlights how easily this set cuts through cold-rolled steel and brass compared to standard high-speed steel and even some premium machinist bits. The included compartmentalized case uses laser-etched labels, making size identification quick on a cluttered bench.
Two practical trade-offs: the clear plastic front cover on the case can crack if dropped onto concrete, and the bits are over-engineered for softwood or drywall work, so hobbyists drilling only occasional holes in mild steel may find the cost per bit higher than necessary. For anyone who regularly faces gummy metals or hardened alloys, this set delivers the longest usable edge life in this lineup.
What works
- TiAlN coating withstands 900°C heat for sustained stainless cutting
- M35 cobalt base maintains edge hardness under heavy loads
- Three-flat shanks prevent chuck spin on larger diameters
What doesn’t
- Clear plastic case lid is prone to cracking in drops
- Overkill for users drilling only mild steel or wood
2. DEWALT DW1361 21-Piece Titanium Pilot Point Set
DEWALT’s DW1361 uses a pilot-point grind that steps the tip, creating a sharp spur that starts the cut on contact without walking. This geometry is especially effective on thin sheet metal where a standard twist bit would skate across the surface before engaging. The titanium nitride coating adds lubricity, reducing the heat buildup that dulls uncoated HSS bits during repetitive drilling sequences.
The twenty-one-bit set spans 1/16-inch to 1/2-inch with duplicates of the most commonly demanded small sizes, so replacing a broken 1/8-inch bit does not require buying a whole new set. The tapered web design thickens toward the shank, improving resistance to torsional breakage when drilling through harder metals like cold-rolled steel or cast iron. Users report that these bits stay sharp noticeably longer than bargain-bin HSS sets, especially when used with standard cordless drills in construction environments.
One limitation: only the bits above 1/4-inch include the full pilot-point geometry, meaning the smaller sizes behave more like conventional split-point bits. A few users also note that the bits can pull aggressively into harder steel once the spur catches, requiring careful pressure control to avoid grabbing too deep. For general metal drilling at a practical price, this set remains the most balanced option across material types.
What works
- Pilot point tip eliminates walking on flat metal surfaces
- Duplicates of small bits reduce downtime from breakage
- Tapered web design improves shank durability under torque
What doesn’t
- Pilot point only on bits 1/4-inch and larger
- Can grab aggressively on harder steel if feed pressure is too high
3. HIGHFIRE 22-Piece Hex Shank Drill Bit Set
HIGHFIRE engineered this set specifically for impact drivers, using a 1/4-inch hex shank that locks into quick-change chucks without spinning or slipping. The hex geometry is critical when high torque is transmitted through the bit: a round shank would rotate inside the chuck jaws, but the hex faces transfer rotational force directly to the cutting edge. The 135-degree split point self-centers even on curved surfaces like metal tubing or conduit.
The set includes 22 bits from 1/16-inch to 1/2-inch, with duplicates of the most frequently fractured sizes. The tapered web design strengthens the flute spine near the shank, reducing the risk of snap-off when drilling through harder materials under heavy feed pressure. The titanium nitride coating extends the working life of each bit by reducing friction and heat accumulation during sustained drilling runs.
Some users report that the bits perform identically to Milwaukee’s hex shank sets at a lower cost per piece, though the packaging is a blister pack rather than a reusable case. The straight shank design means these bits cannot be used in standard three-jaw chucks without an adapter, limiting their utility for users who switch between a drill press and an impact driver. For anyone who primarily uses an impact driver for metal fabrication, this set offers the most secure chuck connection in this roundup.
What works
- Hex shank eliminates slippage in impact driver chucks
- 135° split point drills curved surfaces without walking
- Tapered web resists torsional breakage under pressure
What doesn’t
- Blister pack provides no organized storage
- Not compatible with standard three-jaw chucks without adapter
4. Drill Hulk 6-Piece 1/4-Inch Titanium Hex Shank Bit
Drill Hulk uses M2 high-speed steel, which delivers a well-balanced combination of toughness and edge retention for medium-hard materials like mild steel, aluminum, and PVC. The titanium nitride coating improves chip flow through the flutes and reduces the friction that leads to premature dulling. Each bit has a 1/4-inch hex shank that fits directly into impact driver chucks and quick-change systems without needing an adapter.
The six-bit pack provides only the 1/4-inch size, which is the most commonly used diameter for pilot holes and sheet metal fastening. Users replacing broken bits from larger sets find this focused pack convenient because it avoids paying for sizes they already own.
The main practical limitation is the single diameter offering: if your work requires multiple sizes, you will need to buy separate packs or a full set. Additionally, these bits are best suited for softer metals rather than stainless steel or hardened alloys, where the M2 base will lose its edge faster than cobalt alternatives. For quick-change metal drilling where 1/4-inch is the only size needed, this pack delivers solid value without the bulk of a full case.
What works
- M2 HSS provides good toughness for mild steel and aluminum
- Hex shank locks tightly into impact driver chucks
- Compact pack ideal for replacing lost or broken 1/4-inch bits
What doesn’t
- Only one diameter available in the pack
- Not suited for hardened steels or stainless alloys
5. PLATINUMEDGE 99-Piece Metric Titanium Twist Drill Bit Set
PLATINUMEDGE offers the broadest size range in this lineup with 99 metric bits running from 1.5 mm up to 10 mm, including multiple duplicates of the most commonly broken small diameters like 2 mm, 2.5 mm, and 3 mm. The bits are made from 4241 high-speed steel with a titanium-coated finish that resists surface rust and adds a layer of wear resistance against aluminum, cast iron, and plastics. The 135-degree split point on each bit helps keep the drill centered without aggressive downward pressure.
The plastic storage box organizes every bit in labeled rows, making it easy to find the correct size and quickly replace a broken duplicate without scrounging through drawers. User feedback notes that the bits closely resemble the finish and performance of Harbor Freight titanium sets but cost slightly more per set. The primary advantage over those cheaper alternatives is the inclusion of multiple duplicates for the sizes most likely to snap during use, effectively paying for itself after the first few replacement cycles.
The 4241 HSS base is less heat-resistant than M2 or cobalt steels, so these bits dull faster when drilling into stainless steel or hardened alloys. The titanium coating helps in aluminum and mild steel but does not compensate for the base alloy’s lower red-hardness threshold. For hobbyists who work primarily with soft metals and need a huge variety of metric sizes without a large per-set investment, this set offers the highest piece count per dollar in this comparison.
What works
- 99 bits cover metric sizes from 1.5 mm to 10 mm
- Duplicates of fragile small sizes reduce downtime
- 135° split point provides decent self-centering for soft metals
What doesn’t
- 4241 HSS base dulls quickly in stainless steel
- Finish and edge retention comparable to budget-tier sets
Hardware & Specs Guide
135° Split Point Geometry
The included angle at the tip determines how the bit interacts with the work-hardened layer on metal surfaces. A 135-degree split point fractures that hardened layer and creates a chisel edge that walks less than a standard 118-degree point. This geometry also reduces the downward feed force required, which is especially important when drilling with lower-torque cordless drills.
TiAlN Coating vs TiN
Titanium aluminum nitride forms a ceramic-like barrier that resists oxidation up to 900°C, compared to titanium nitride which degrades around 600°C. The aluminum component creates aluminum oxide at high temperatures, which lubricates the flute and transfers heat away from the cutting edge. For stainless steel and high-alloy work, TiAlN coating is the difference between clean holes and heat-burned edges.
M35 Cobalt Steel
M35 high-speed steel contains 5% cobalt, which raises the temperature at which the steel’s crystalline structure softens. This red-hardness property allows the bit to maintain cutting edge integrity at the high temperatures generated during continuous drilling in hardened materials. Cobalt bits are more brittle than standard HSS but significantly more heat-resistant.
Tapered Web Design
The web is the central metal spine between the flutes. A tapered web starts thin near the tip for easier penetration and gradually thickens toward the shank for maximum torsional strength. This progressive thickness resists the twisting force that causes bit breakage during deep plunges into tough metals, without sacrificing the tip’s ability to start a cut cleanly.
FAQ
What is the best coating for drilling stainless steel?
Can I use wood drill bits on metal?
Final Thoughts: The Verdict
For most users, the best drill bits for metal winner is the OSTTE M35 Cobalt 14-Piece Set because its TiAlN coating and 5% cobalt base handle stainless steel and hardened alloys without premature edge breakdown. If you want a pilot-point tip that starts on contact without a center punch, grab the DEWALT DW1361 21-Piece Set. And for impact driver users who need a hex shank that never slips in the chuck, nothing beats the HIGHFIRE 22-Piece Hex Shank Set.