Best Drill Bit Sets
Coating is the whole decision, and the names are not marketing. Black oxide is plain high speed steel with a surface treatment, fine for wood and mild steel. Titanium nitride is a hard coating over high speed steel that lasts longer in the same materials. Cobalt is different in kind: the cobalt is alloyed through the steel, not coated on, so it survives the heat of drilling stainless and hardened steel.
That difference matters because a titanium bit used on stainless will dull in one hole, and people conclude the bit was bad when it was the wrong bit. Each set below is listed by what it is actually made of and what it can cut.
Quick answer
For general work the DeWalt 21 piece titanium nitride pilot point set is the right default, because the pilot point tip stops the bit walking and the coating lasts in wood and mild steel. For stainless or hardened steel you need cobalt, where the Bosch CO21B is the sensible choice. The Irwin left hand set is for one job only, extracting broken bolts.
Why trust ToolBuyerHub
- Every set here is a named brand sold on Amazon US, checked against the live listing
- Specifications come from manufacturer and listing data, not from guesswork
- Owner-feedback themes are summarized as feedback, never as our own hands-on testing
- No invented star ratings; the Research Score criteria are visible on each pick
- Sets are grouped by steel and coating, because that decides what they can actually drill
- The difference between a coated bit and an alloyed cobalt bit is stated plainly rather than blurred
Research updated October 2026.
What Matters Most When Buying Drill Bits
Material and coating first. Black oxide high speed steel handles wood, plastic and mild steel and is the cheapest. Titanium nitride is a hard coating on high speed steel that extends life in the same materials, but once the coating wears at the cutting edge the bit underneath is ordinary steel again, so you cannot sharpen it and keep the benefit. Cobalt bits have cobalt alloyed through the whole bit, which raises the temperature it can work at, and that is what lets it drill stainless and hardened steel; it can also be resharpened without losing its properties. Tip geometry comes second: a split point or pilot point tip self-centres so the bit does not wander, which matters most on metal and on smooth surfaces. Then check the size range for gaps, and whether the shank suits your tool, since hex shank bits lock into an impact driver while round shanks need a drill chuck.
| Model | Best for | Key specs | Research Score |
|---|---|---|---|
| DeWalt 21 Piece Titanium Nitride Coated Pilot Point Drill Bit Set | General wood, plastic and mild steel | HSS, titanium nitride coated, Pilot point | 92/100 |
| Bosch CO21B 21 Piece Cobalt M42 Metal Drill Bit Set with Case | Stainless and hardened steel | Cobalt M42, Stainless, hardened steel | 94/100 |
| DeWalt 21 Piece Black and Gold Oxide High Speed Steel Drill Bit Set | Cheap bits you will use up | HSS, black and gold oxide, 21 | 87/100 |
| Milwaukee 48-89-4631 Shockwave Titanium Nitride Drill Bit Kit, 23 Piece | Use in an impact driver | HSS, titanium nitride, Impact rated hex | 90/100 |
| Drill Hog 29 Piece Cobalt M42 Drill Bit Set with Steel Case | A cobalt set you keep resharpening | Cobalt M42, 29 | 91/100 |
| Irwin Left Hand Drill Bit Set, Cobalt Alloy Steel, 5/64 in to 19/64 in | Extracting broken bolts and studs | Left hand, Cobalt alloy steel | 89/100 |
| Makita B-49373 75 Piece Metric Drill and Screw Bit Set | One case for drilling and driving | Drill and screwdriver bits, Metric drill sizes | 86/100 |
DeWalt 21 Piece Titanium Nitride Coated Pilot Point Drill Bit Set
Best OverallPros
- Pilot point tip self-centres, so the bit does not walk across the surface before biting
- Titanium nitride coating noticeably extends life against uncoated bits in wood and mild steel
- Twenty one sizes covers the common range without gaps for general work
Cons
- Not suitable for stainless or hardened steel, where it will dull in a hole or two
- Once the coating wears off the cutting edge, sharpening leaves you with plain HSS
The default set for a workshop or a toolbox. The pilot point tip is the feature that earns it the top spot: a conventional twist bit skates across sheet metal or a smooth surface until it finds a divot, which is how holes end up off-centre, and a self-centring tip removes that. The coating is a genuine durability gain within its materials. Understand the limit and buy cobalt separately for stainless.
Bosch CO21B 21 Piece Cobalt M42 Metal Drill Bit Set with Case
Best for MetalPros
- Cobalt is alloyed through the bit, not coated, so heat resistance does not wear away
- M42 grade handles stainless steel, which destroys titanium coated bits
- Can be resharpened without losing its heat resistance, unlike a coated bit
Cons
- Costs considerably more than coated HSS sets of the same size count
- More brittle than plain HSS, so it chips if the drill is allowed to wobble or snatch
This is the set to own if you drill metal properly. The distinction matters: a coated bit is ordinary steel with a hard skin, and once that skin wears at the edge the bit softens immediately in a hot hole. Cobalt is alloyed throughout, so it keeps working at the temperatures stainless generates. Use cutting fluid, run slower than you think and let the bit cut rather than leaning on it.
DeWalt 21 Piece Black and Gold Oxide High Speed Steel Drill Bit Set
Best ValuePros
- Cheapest honest way to get a full size range from a known brand
- Oxide finish resists rust and reduces friction against bare HSS
- Easy to replace individual sizes, since drill bits are consumables
Cons
- Shorter life than titanium coated bits in the same materials
- No use at all on stainless or hardened steel
Drill bits are consumables, and this is the set that acknowledges it. For general wood and mild steel work, the practical difference between oxide and titanium is how many holes you get, not whether the hole is good. If you break and lose bits, as most people do, buying cheaper and replacing more often is a reasonable strategy. Just keep a cobalt set for the jobs that need it.
Milwaukee 48-89-4631 Shockwave Titanium Nitride Drill Bit Kit, 23 Piece
Best for Impact DriversPros
- Impact rated with a hex shank, so it locks into an impact driver instead of slipping in a chuck
- Shockwave bits are built to take the rotational hammering that snaps ordinary bits
- Widely stocked, which matters for a consumable you replace mid job
Cons
- Hex shank is less precise in a drill chuck than a round shank for fine work
- Still titanium coated HSS, so stainless remains out of scope
Worth having if your main tool is a cordless impact driver rather than a drill. An impact driver delivers rotational hammer blows, and ordinary round shank bits both slip and snap under that. A hex shank locks in and an impact rated bit is built to flex rather than shear. For precision holes in metal, use a drill and a round shank bit instead.
Drill Hog 29 Piece Cobalt M42 Drill Bit Set with Steel Case
Best Premium CobaltPros
- Twenty nine sizes gives much finer size coverage than a 21 piece set
- Cobalt M42 throughout, so it handles stainless and can be resharpened
- Steel index case survives a van and keeps sizes ordered
Cons
- A significant outlay, and overkill if you rarely drill metal
- Cobalt brittleness means a wobbling drill or a snatch will chip the edge
The pick if metal drilling is a regular part of your work and you would rather resharpen than replace. Finer size coverage is the practical benefit people underrate, because in metal work the exact hole size often matters, whether for a tap or a close fit fastener. Combined with a steel index case, this is a set that lasts years rather than a season.
Irwin Left Hand Drill Bit Set, Cobalt Alloy Steel, 5/64 in to 19/64 in
Best for Broken BoltsPros
- Cuts in reverse, so the drilling action itself tends to back a broken bolt out
- Cobalt alloy, which is necessary since snapped fasteners are often hardened
- Frequently removes a broken stud without needing an extractor at all
Cons
- Useless as general purpose bits, since they only cut in reverse
- Narrow size range, aimed at small fasteners rather than large studs
A single purpose set that is genuinely worth owning before you need it. When a bolt snaps flush, the standard approach is to drill it and use an extractor, and the drilling often tightens the remains further. A left hand bit cuts as the drill runs in reverse, so the cutting torque works to unscrew the broken piece, and surprisingly often the stub simply walks out during drilling. Cobalt matters because snapped bolts are usually hard.
Makita B-49373 75 Piece Metric Drill and Screw Bit Set
Best Combo SetPros
- Covers drilling and driving in one case, so there is one thing to carry rather than two
- A 75 piece count gives real depth in the common sizes
- Metric drill sizes, which suit European and imported hardware
Cons
- Piece count includes screwdriver bits, so the drill bit coverage is narrower than 75 suggests
- Not a specialist set, so there is no cobalt here for stainless work
A practical choice if you want one case that handles a whole job rather than the best bits in each category. Combination sets always involve this trade: the count looks large because screwdriver bits are cheap to include, and the drill bit range is more modest than the headline implies. Read the contents rather than the number. For general home and site work, having both in one place is genuinely convenient.
Black oxide, titanium or cobalt
Black oxide is plain high speed steel with a surface treatment that resists rust and reduces friction. It drills wood, plastic and mild steel and is cheapest. Titanium nitride is a hard ceramic coating over high speed steel, which extends life in those same materials, but it is a skin: once it wears at the cutting edge, the steel underneath is ordinary HSS, and sharpening removes the benefit permanently. Cobalt is a different material rather than a coating, with cobalt alloyed through the whole bit, which raises its working temperature enough to drill stainless and hardened steel and lets it be resharpened without loss. Buying titanium for stainless is the single most common mistake in this category.
Tip geometry and why bits wander
A conventional twist bit has a chisel-shaped point that has to be forced into the surface before it starts cutting, which is why it skates across sheet metal and smooth surfaces until it catches. A split point or pilot point tip comes to a sharper self-centring point that begins cutting immediately, which both stops the walk and reduces the force needed. On metal, a centre punch dimple still helps. On wood, brad point bits have a sharp central spur and are better again, though they are wood specific and useless on metal.
Speed, pressure and cutting fluid
Most burnt bits were run too fast with too much pressure. Larger diameters need slower speeds, because the cutting edge at the outside of a big bit travels much further per revolution than on a small one and overheats. In metal, use cutting fluid or even light oil, apply steady moderate pressure and let the bit produce a continuous curl of swarf; dust rather than curls means it is rubbing, not cutting, which destroys the edge in seconds. In stainless, the extra rule is never let the bit stop spinning in the hole, since stainless work hardens and you will not get back through the hardened layer.
Shanks, impact drivers and size gaps
Round shank bits grip in a three jaw drill chuck and are more concentric, so they are better for precise holes. Hex shank bits lock into an impact driver's quick change collet and do not slip, and impact rated bits are built to survive the rotational hammering, which snaps ordinary bits. If your only tool is an impact driver, buy impact rated hex shank bits. Whatever you buy, check the size range for gaps in the middle, where cheap sets economise, and remember bits are consumables, so easy single size replacement is a real advantage.
FAQs
What is the best drill bit set to buy?
For general wood, plastic and mild steel work, the DeWalt 21 piece titanium nitride pilot point set, because the self-centring tip stops the bit walking and the coating extends life. If you drill stainless or hardened steel, you need cobalt instead, such as the Bosch CO21B, since titanium coated bits dull almost immediately in stainless.
What is the difference between titanium and cobalt drill bits?
Titanium nitride is a hard coating applied over ordinary high speed steel, so it is a skin that eventually wears through and cannot be sharpened back. Cobalt bits have cobalt alloyed through the entire bit, which raises the temperature they can work at and lets them drill stainless and be resharpened. Cobalt is a different material, not a better coating.
What drill bits do I need for stainless steel?
Cobalt, specifically M35 or M42 grade. Stainless generates a lot of heat and work hardens, so a coated HSS bit loses its edge almost immediately. Use cutting fluid, run at a slow speed, apply steady pressure and never let the bit stop turning in the hole, because the hardened layer it creates is very hard to drill through again.
Why do my drill bits keep breaking or burning?
Usually too much speed, too much pressure, or no lubrication in metal. Large diameters need slower speeds, since the outer cutting edge travels further per revolution and overheats. If the bit produces dust rather than curls of swarf it is rubbing instead of cutting, which ruins the edge in seconds. In an impact driver, ordinary non-impact bits snap at the shank.
What is a pilot point or split point drill bit?
A tip ground to a sharper self-centring point that begins cutting immediately instead of needing to be forced in. The practical benefit is that the bit does not skate across the surface before biting, so holes land where you marked them. It matters most on sheet metal and smooth surfaces, and reduces the pressure needed on all materials.
Can I use regular drill bits in an impact driver?
You can fit hex shank ones, but ordinary bits are not built for the rotational hammering an impact driver produces and will snap at the shank. Use impact rated bits with a hex shank, such as the Milwaukee Shockwave set. Round shank bits will also slip in a quick change collet, so they need a drill chuck.
What are left hand drill bits for?
Removing broken bolts and studs. They cut while the drill runs in reverse, so the cutting torque acts to unscrew the broken fastener rather than tighten it, and the stub often backs itself out during drilling. They are cobalt because snapped fasteners are usually hardened, and they are useless for ordinary drilling since they only cut in reverse.
How many drill bits do I need in a set?
Coverage matters more than count. For general work, a continuous fractional range from about 1/16 to 1/2 inch, which is roughly 21 to 29 sizes, covers almost everything. Watch out for combination sets where a large headline count is made up largely of screwdriver bits rather than drill bits, and check for skipped sizes in the middle of the range.
Can drill bits be sharpened?
Cobalt and plain HSS bits can be sharpened and keep their properties, which is a real argument for cobalt if you drill metal regularly. Titanium coated bits can be sharpened mechanically, but doing so removes the coating at the cutting edge, leaving ordinary high speed steel, so the durability advantage you paid for is gone after the first sharpening.
Our verdict
Buy the DeWalt titanium nitride pilot point set for general work, and buy cobalt separately rather than expecting one set to do everything: the Bosch CO21B for occasional metal, or the Drill Hog 29 piece if you drill metal often and want to resharpen. Add the Milwaukee Shockwave set if your main tool is an impact driver, and keep the Irwin left hand set in the drawer for the day a bolt snaps flush.