Anyone who has snapped a cheap bit against a stainless bracket knows the frustration: heat builds up, the tip dulls, and the hole never quite starts where you wanted it to. The five sets below solve that problem with cobalt-infused steel, self-centering points, or full size ranges that cover everything from pilot holes to half-inch bores. Whether you’re a weekend DIYer mounting hardware into cast iron or a shop tech running repeated holes in hardened steel, there’s a match here for your drill press or cordless driver.
A Quick View Of The Lineup
Narwhal 1/8 Inch Cobalt Drill Bits, 13 Pack M35
CaRoller 29Pcs Drill Bit Set, High Speed Steel
RCINDUS 20PCS 3/16″ Cobalt Drill Bits HSS M35
RCINDUS 20PCS 1/8″ Cobalt Drill Bits HSS M35
AUYAARS 19 Pcs Hex Shank Drill Bit Set Titanium
Inside Each Recommended Option
A single-size pack sounds limiting until you realize how much 1/8-inch drilling actually happens in a working shop: pilot holes before tapping, sheet-metal fasteners, hinge screws. This Narwhal set commits fully to that one job, using M35 high-speed steel with 5% cobalt content, an alloy that holds its edge at the higher temperatures hard steel generates.
The 135-degree split point is the detail that matters most in practice. Instead of skating across a polished surface until it finds its mark, the tip bites immediately, which means less center-punching and cleaner starts in stainless. At 2.55 inches overall with a 1-3/8-inch flute, these jobber-length bits reach through most common stock without whipping.
Notable Upsides
- Cobalt alloy resists the heat softening that kills ordinary bits in stainless
- Split point starts on target, cutting down on wandering and rework
- Thirteen pieces mean spares are on hand when one bit finally wears out
- Fully ground flutes produce a consistent hole diameter across the pack
- Included plastic case keeps loose bits from scattering through a toolbox drawer
Honest Caveats
- One diameter only, so this is a supplement to a set rather than a replacement
- The plastic case is functional but basic; owners commonly report it works best stored flat
The Details
Who It Suits Best
Machinists and serious DIYers who burn through 1/8-inch bits on a regular basis and want industrial-grade replacements in bulk.
Where A Sibling Pick Shines
For a full range of diameters in one purchase, the CaRoller 29-piece set covers every fractional size from 1/16 to 1/2 inch instead.
Where the Narwhal pack doubles down on a single size, this CaRoller kit spreads across twenty-nine fractional sizes, from hair-thin 1/16 inch up to a substantial 1/2 inch bore. That span covers nearly every threaded fastener pilot you’ll encounter around a home workshop, which is why it earns a permanent spot in many tool chests.
These are straight high-speed steel bits with a 135-degree tip, so they’re happiest in mild steel, aluminum, wood, and plastic. In our view, that’s exactly the right tool for household repairs and general building tasks; pushing them into hardened stainless day after day is asking more than the alloy is designed to give.
Practical Pluses
- Nearly complete fractional range eliminates mid-project trips to buy one missing size
- 135-degree tip helps the larger diameters start cleanly without excessive pressure
- Covers both delicate electronics-scale holes and half-inch anchor pilots
Points To Note
- Standard HSS lacks cobalt, so expect faster wear in stainless or hardened alloys
- Twenty-nine loose pieces reward disciplined storage; a labeled index keeps sizes findable
Right Fit For
Home DIYers and general builders who want one organized set covering virtually every common drilling task short of exotic metals.
Swap It Out When
Stainless and cast iron dominate your workload; either RCINDUS cobalt pack will outlast this set in those materials.
Three-sixteenths is one of those unglamorous sizes you reach for constantly: clearance holes for #10 screws, anchors, small tubing. Getting twenty of them in M35 cobalt steel changes the economics of wear, because even if a few dull over a season of stainless work, you’ve got plenty in reserve.
Compared with the Narwhal 1/8-inch pack reviewed above, this one trades a smaller diameter for more muscle behind each hole, and the same 5% cobalt chemistry carries over. The 135-degree split point gives it that same no-walk start on curved or polished surfaces, something you’ll appreciate drilling round bar stock.
The Practical Payoff
- Cobalt-alloyed steel stays sharp longer than plain HSS in tough metal
- Self-centering tip cuts setup time on rounded or slippery workpieces
- Versatile across steel, cast iron, hard plastic, and wood in one bit
- Twenty pieces suit production-style repetition without constant reordering
Small Limitations
- Single-diameter pack again, so plan it alongside a general-purpose set
- Cobalt bits are brittle compared to softer steel; sideload can snap one, so keep the drill square
Quick Facts
Who Will Love This
Fabricators and maintenance techs running repeated 3/16-inch holes in structural or stainless material.
Another Choice May Suit
Light-duty home projects with mostly wood and soft metal are better served by the AUYAARS titanium hex-shank set.
This is the direct rival to the Narwhal pack at the top of the list, matching its 1/8-inch diameter, M35 cobalt construction, and 135-degree split point, but shipping seven extra bits. For anyone drilling starter holes by the dozen, that quantity difference is real money over a year of use.
Thin bits like these live and die by breakage, and the cobalt alloy’s hardness is a double-edged sword: excellent wear life when the drill runs true, but less forgiveness for a bent approach angle. Keep the chuck tight and the pressure steady, and owners commonly report these lasting through long stainless sessions.
Positive Takeaways
- Twenty bits per pack stretch your cost per hole way down
- Same 5% cobalt metallurgy as pricier single-brand packs
- Split point removes most of the center-punching step on flat stock
- Plastic storage case keeps the small bits contained and sorted
Things To Consider
- Hardened tips snap under side load, so technique matters more than with cheaper soft steel
- Only one size; pair it with a broader set for full coverage
Made For
Volume users, from hobbyist gunsmiths to HVAC installers, who treat 1/8-inch pilot drilling as a daily routine.
Look Elsewhere When
You need multiple diameters in one box; the CaRoller 29-piece set handles that spread far better.
Not every drilling job involves hardened steel, and this AUYAARS set is built for the rest of it. Nineteen hex-shank twist bits run from 1/16 to 1/4 inch, made from 4241 high-speed steel with a uniform titanium coating that reduces friction and helps chips clear smoothly.
The hex shank is the headline convenience. Unlike the round shanks on every other pick here, a hex profile locks into quick-release chucks and impact drivers without slipping, so swapping sizes takes seconds instead of fumbling with a chuck key. That matters enormously when you’re moving between pilot holes on a deck build or furniture assembly.
Useful Strengths
- Hex shanks drop straight into quick-change chucks with zero slippage
- Titanium coating cuts friction, keeping heat and wear down in everyday use
- Size range suits household repairs, woodworking, plastic, and light metal
- Balanced durability-to-cost ratio makes losing one far less painful
Trade Offs
- Titanium-coated HSS sits below true cobalt for sustained stainless or cast iron work
- Tops out at 1/4 inch, leaving larger holes to another set
Feature Rundown
The Right Fit
New DIYers and homeowners whose projects mix wood, plastic, and occasional thin metal rather than heavy fabrication.
Reach For A Different Pick When
Your week revolves around stainless steel; the RCINDUS 3/16-inch cobalt pack is engineered specifically for that grind.
What Matters Most Before Choosing Metal Drill Bits For Steel
Match The Metallurgy To The Job
The single biggest decision is the steel itself. Plain high-speed steel handles wood, plastic, aluminum, and mild steel fine, while M35 cobalt steel, which blends about 5% cobalt into the alloy, holds hardness at the elevated temperatures that stainless and cast iron generate. Paying for cobalt when you rarely touch hard metal is wasted budget, and skipping it when you do is a false economy.
Point Geometry Changes Everything
A 135-degree split point self-centers as it spins, biting into the surface instead of skating across it. Standard 118-degree points need a center punch and steadier hands. For overhead work or drilling round stock, the split point’s automatic starting behavior saves time and reduces broken bits considerably.
Size Range Versus Quantity
Decide what you’re optimizing for. Full-range sets like the CaRoller cover dozens of diameters for varied projects, while single-size bulk packs like the RCINDUS options win on cost per hole when one size dominates your work. Most shops end up with both approaches in the drawer.
Shank And Storage Fit
Round shanks suit traditional chucks and drill presses; hex shanks favor quick-change drivers. And don’t overlook the case, since twenty-nine loose bits without an indexed holder becomes a sorting chore within a week.
Key Considerations Across These Picks
Traps First Timers Fall Into
The classic error is buying a bargain HSS set for stainless work, then wondering why three bits dulled in an afternoon. Another common slip is running too fast with too little pressure, which work-hardens the surface and makes every following bit struggle. Match speed and feed to the material, not the other way around.
Where The Extra Money Goes
Cobalt content, precision grinding, and split-point geometry account for most of the price gap between entry and upper-tier bits. In our view, that premium pays for itself quickly once your workload includes hardened alloys, because worn bits cost more in ruined workpieces than the upgrade ever will.
Frequently Asked Questions
Can cobalt drill bits be sharpened?
Yes, cobalt bits accept regrinding on a bench grinder or drill doctor just like standard HSS. Their harder composition simply means you’ll sharpen them less often.
What speed should I use for drilling steel?
Slower is generally right, often a fraction of the speed used for wood, especially in larger diameters. Lower RPM with steady pressure keeps heat manageable and preserves the cutting edges.
Do I still need cutting oil?
For stainless and thicker mild steel sections, a few drops of cutting oil noticeably extend bit life. Thin sheet metal often drills fine dry with a split-point bit.
Why does my drill bit walk on metal?
A conventional 118-degree tip has no self-centering action, so it skates on smooth surfaces until friction catches. A 135-degree split point or a center punch solves this.
Are titanium-coated bits the same as cobalt?
No, titanium coating is a surface treatment on standard HSS that reduces friction, while cobalt is an alloy change throughout the bit. Cobalt wins for sustained hard-metal drilling once the coating would otherwise wear away.
Closing Remarks
Steel rewards the right bit and punishes the wrong one, usually within the first hole. Start by naming your actual workload, then match the alloy, geometry, and pack style to it rather than chasing the biggest number of pieces. Any of the five above will serve you honestly within its lane, and choosing deliberately now means fewer snapped bits and cleaner holes later.
