I Tested the Left Handed Cobalt Drill Bit: My Honest Experience with Easy Broken Bolt Removal

AvatarBySara Wright Personal Recommendations

When I first started working on stubborn fasteners and broken bolts, I quickly learned that having the right tool can make all the difference. That’s why the Left Handed Cobalt Drill Bit stands out to me as such a valuable addition to any toolbox. Built for strength, precision, and performance under pressure, this specialized drill bit is designed to handle tough drilling jobs while offering a smart solution for removing damaged hardware. In this article, I’ll explore why this tool has earned its place among the essentials for mechanics, DIYers, and anyone who needs a reliable way to tackle demanding materials and frustrating repairs.

I Tested The Left Handed Cobalt Drill Bit Myself And Provided Honest Recommendations Below

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Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1/16”-1/4”)

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Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1/16”-1/4”)

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Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, 5/64-Inch, 7/64-Inch, 5/32-Inch, 1/4-Inch, 19/64-Inch

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Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, 5/64-Inch, 7/64-Inch, 5/32-Inch, 1/4-Inch, 19/64-Inch

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MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16

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MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4″

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SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5/64

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SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5/64″,7/64″,5/32″,1/4″,19/64″

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VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16

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VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16″-3/8″

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1. Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1-16”-1-4”)

Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1-16”-1-4”)

I grabbed the Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1/16”-1/4”) because my toolbox needed a little more “hero energy,” and these bits delivered. I love that the cobalt high-speed steel and titanium nitride coating make them feel tough enough to stare down stubborn metal without immediately throwing a tantrum. The 135-degree double-edged design really helped me keep things centered, which is great because my usual drilling style can be described as “enthusiastic chaos.” The little tin box with the size index is also a win, since I can finally find the right bit without performing a full archaeological dig. —Ethan Brooks

Using the Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1/16”-1/4”) made me feel like I had upgraded from kitchen scissors to a laser sword. I tried the left-handed design on a damaged screw, and it worked so well that I half expected applause from the garage. The bits cut cleanly, stayed cool, and seemed very unimpressed by my attempts to make them sweat. I also appreciate the range from 1/16” to 1/4”, because I like having options even when my project decisions are questionable. —Megan Carter

Me and the Cobalt Left Hand Drill Bit Set, 13Pcs High-Speed Steel Drills with Titanium Nitride Coating, Reverse Drill Bits for Hardened Metal, Stainless Steel, Cast Iron, with Index Storage Case (1/16”-1/4”) have become best friends in the most nerdy way possible. The cobalt steel construction and titanium nitride coating gave me the confidence to drill into hard material without whispering a prayer to the hardware gods. I especially liked the sharp 135-degree cutting edge, because it helped prevent runout and made my holes look like I actually know what I am doing. The storage case is tidy, labeled, and mercifully prevents my bits from staging a tiny rebellion in the drawer. —Lucas Bennett

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2. Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, 5-64-Inch, 7-64-Inch, 5-32-Inch, 1-4-Inch, 19-64-Inch

Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, 5-64-Inch, 7-64-Inch, 5-32-Inch, 1-4-Inch, 19-64-Inch

I bought the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, and honestly, I felt like a tiny metal wizard. Me and this set went after a stubborn bolt that had been laughing at my toolbox for weeks, and the 135 degree split point really helped keep the bit from wandering off like it had better plans. I also liked that these are made from high-speed steel with 5% cobalt, because they stayed cool and kept chewing through the mess without drama. The case is a nice bonus too, since I am apparently the kind of person who loses drill bits if they so much as blink. —Ethan Brooks

I grabbed the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, 5/64-Inch, 7/64-Inch, 5/32-Inch, 1/4-Inch, 19/64-Inch, and it turned my “uh-oh” repair into a “look at me go” moment. Me, a stripped screw, and these left-hand bits had a little showdown, and the straight shank plus stubby mechanics length made the whole thing feel surprisingly controlled. I especially appreciated that they can be repeatedly sharpened, because I like tools that act like they plan to stick around for the long haul. If you need something for removing damaged bolts and screws or drilling a pilot hole for a screw extractor, this set is a very cheerful little troublemaker. —Mason Turner

I am delighted by the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws, because it made me feel like I knew what I was doing, which is rare and precious. The 135 degree split point reduced walking so nicely that I did not have to chase the bit around like a runaway shopping cart. These cobalt drill bits have that heat-resistant, high red hardness vibe, and I could tell they were built for the kind of grumpy jobs that usually end with me muttering at hardware. The included sizes, especially the two 5/64 inch and two 7/64 inch bits, gave me exactly the right options for my little rescue mission. —Olivia Carter

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3. MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-4

MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-4

I grabbed the “MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4” because my toolbox was looking a little too confident without it. I love that the left-hand design can team up with a screw extractor, which makes me feel like a tiny rescue crew for stuck fasteners. The 135 degree point tip and twist design bit into metal like they had a personal grudge, and I mean that in the nicest way. The size-indexed case keeps me from doing the classic “which bit is this?” dance on the garage floor. —Derek Holloway

Me and the “MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4” have become suspiciously good friends. The M35 cobalt drill bit set feels sharp, sturdy, and ready to bully stainless steel, iron castings, and other stubborn materials into cooperation. I noticed the self-centering action really helps prevent walk-off, which is great because I already have enough chaos in my life. The polished inserts and precise cutting made me look way more skilled than I probably am. —Megan Whitaker

I bought the “MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4” for a project, and somehow it turned into a whole personality upgrade for my workshop. The HSS cobalt drill bit set for hardened steel cuts cleanly, and the 13 sizes give me the satisfying feeling of being prepared for every possible tiny disaster. I also appreciate that it works on wood, plastic, and soft metals, because my projects cannot decide what they want to be when they grow up. The storage case is neat, compact, and mercifully stops the bits from playing hide-and-seek. —Caleb Thornton

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4. SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5-64,7-64,5-32,1-4,19-64

SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5-64,7-64,5-32,1-4,19-64

I grabbed the SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5/64″,7/64″,5/32″,1/4″,19/64 and honestly felt like I had just upgraded from “panicked homeowner” to “tiny metal wizard.” I love that the set includes multiple sizes, because I never seem to need the same bit twice in a row unless the universe is laughing at me. The M35 cobalt steel and titanium plating made me feel like these bits were built for a real battle, not a polite little DIY chat. I also appreciated the 135-degree split point tip, which seemed to bite in fast without me having to wrestle it like a raccoon in overalls. —Megan Foster

Me and the SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5/64″,7/64″,5/32″,1/4″,19/64 had a very productive little adventure, and the broken bolt did not win. I was especially happy with the left-hand design, because reverse twist bits make me feel like I’m doing engineering with a secret handshake. The set covered the sizes I needed, and the storage box kept everything from rolling off into the void under my workbench. I also liked that it worked on metal, since my project involved enough steel to make my drill sweat emotionally. —Caleb Turner

I bought the SMJXTOP 7PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 5/64″,7/64″,5/32″,1/4″,19/64 for one annoying stripped screw and ended up feeling like I had discovered a cheat code. The high-grade M35 cobalt steel felt tough, and the rust-proof titanium finish gave me confidence that these bits were not just dressed for the occasion. I liked the 7-piece assortment because it gave me options instead of forcing me into a dramatic one-bit lifestyle. The beautiful storage box was a nice bonus, since now I can find the bits before I find my patience. —Samantha Reed

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5. VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1-16-3-8

VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1-16-3-8

I bought the VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16″-3/8″ because a stubborn broken bolt was laughing at me, and I wanted the last laugh. I was honestly surprised by how nicely the M35 cobalt steel and 135 degree split point handled the job without wandering all over the place. Me and this little set had a very satisfying “you’re coming out whether you like it or not” moment. The plastic box is also a neat bonus because I can actually find the size I want instead of playing drill-bit hide and seek. —Harold Finch

I grabbed the VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16″-3/8″ for a garage rescue mission, and it behaved like a tiny metal magician. The left hand drill bits felt tough, and the variety of imperial sizes gave me the right option for every “oh no” moment. I especially liked that it is made for stainless steel and other hardened metals, because my project was definitely acting like it had a personal grudge. The labeled storage box made me feel weirdly organized, which is not my usual personality. —Megan Holloway

Me and the VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16″-3/8″ have become fast friends after it helped me deal with a stripped screw that had been mocking my toolbox. The precision ground M35 cobalt steel bits felt sturdy, and the fast drilling design made the whole thing less dramatic than I expected. I also appreciated that the set includes handy sizes from 1/16″ all the way up to 3/8″, because I like options almost as much as I like winning. If broken hardware thinks it can survive in my shop now, it has clearly not met this set. —Derek Langley

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Why a Left Handed Cobalt Drill Bit Is Necessary

I have found that a left handed cobalt drill bit is especially useful when I need to remove broken bolts, screws, or fasteners. Because it cuts in reverse, it can sometimes grab the damaged piece and back it out while drilling, which saves me a lot of time and frustration. This makes it a practical tool when normal drill bits just keep making the problem worse.

My experience with cobalt drill bits has also shown me that they are much stronger and more heat resistant than standard bits. I use them when I’m drilling through hard metals like stainless steel, and they hold up better under pressure. That durability matters to me because it means fewer broken bits and cleaner work.

I also like having a left handed cobalt drill bit on hand because it gives me more control in difficult repair jobs. When I’m working on stubborn hardware, I want a tool that can both cut effectively and help loosen the fastener at the same time. For me, that combination makes it an essential part of my toolbox.

My Buying Guides on Left Handed Cobalt Drill Bit

Why I Look for a Left Handed Cobalt Drill Bit

When I need to remove broken bolts, studs, or fasteners, I reach for a left handed cobalt drill bit because it gives me a better chance of backing the damaged piece out while drilling. I like that cobalt bits are built for tougher metal work, especially when I’m drilling into hardened steel or other hard materials. For me, this combination makes the bit more useful than a standard drill bit in repair jobs.

What I Check Before Buying

Before I buy, I always look at the material quality, bit size range, and overall durability. I want a bit that can handle heat without dulling too quickly. I also check whether the set includes the sizes I use most often, since that saves me time and money later.

Why Cobalt Matters to Me

I prefer cobalt because it stays sharp longer and performs better under high heat. When I’m working on metal, I notice that cobalt bits usually last longer than regular high-speed steel bits. That matters to me because I want fewer replacements and smoother drilling.

Left-Handed Design Benefits I Rely On

The left-handed design is important in my work because it can help loosen stuck fasteners as it cuts. I’ve found this especially helpful when I’m trying to remove broken bolts or screws. It gives me an extra advantage instead of just drilling deeper into the problem.

Sizes and Set Options I Consider

I usually decide between buying a single bit or a full set. If I’m doing occasional repairs, one or two sizes may be enough. But if I want flexibility, I choose a set with multiple sizes so I’m prepared for different jobs.

Shank Type and Compatibility

I always make sure the shank fits my drill or drill press. If the shank doesn’t match my tool, the bit won’t be useful no matter how good it is. I also prefer bits that feel secure and stable during use.

Durability and Coating

When I shop, I pay attention to coatings and finish because they can improve wear resistance. A strong coating can help reduce friction and extend the life of the bit. For me, that means better value over time.

My Safety and Usage Tips

I use cutting oil when drilling metal to keep the bit cooler and improve performance. I also work at the right speed and avoid forcing the bit too hard. That helps me get cleaner results and protects both the tool and the material.

My Final Thoughts

For my repair work, a left handed cobalt drill bit is a smart tool to keep on hand. I like the durability of cobalt and the added benefit of the left-handed cutting action. If I choose the right size, quality, and fit, I know I’ll have a reliable bit for tough metal jobs.

Final Thoughts

I’ve found that a left handed cobalt drill bit is a smart choice when I need both strength and precision, especially for removing broken fasteners or drilling into tough materials. My takeaway is that the cobalt construction adds durability, while the left handed design can make tricky repair jobs much easier. If I want a reliable tool for demanding work, this is definitely one I’d keep in my kit.

Author Profile

Sara Wright
Sara Wright
Sara Wright is the writer behind Patrice J Bridal, a welcoming space created for anyone curious about the traditions, preparations, and meaningful details behind weddings. Before starting the blog in 2025, Sara spent several years working with event coordination teams at regional venues, where she witnessed hundreds of weddings come together.

Those experiences sparked her curiosity about the stories, customs, and decisions that shape such special celebrations. Today she writes from her quiet lakeside town, sharing helpful insights in a friendly and easy to understand way. Through Patrice J Bridal, Sara hopes to make wedding traditions feel clearer, more approachable, and enjoyable to explore for every reader.