I Tested the Best Left Handed Cobalt Drill Bit for Easy Screw Removal and Precision Drilling

AvatarByMiles Hart

I’ve always been fascinated by the tools that quietly solve some of the toughest problems in a workshop, and the left handed cobalt drill bit is one of those standout essentials. At first glance, it may seem like just another specialized drill bit, but it plays a surprisingly important role when precision, strength, and problem-solving matter most. Whether you’re dealing with stubborn fasteners, broken bolts, or materials that demand extra durability, this tool has a way of proving its value in situations where ordinary bits fall short.

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 I wanted something tougher than my usual “wishful thinking” tools. I’m genuinely impressed by how the cobalt high-speed steel and titanium nitride coating seem to laugh in the face of hard metal. The 135-degree double-edged design helped me stay on target instead of doing my usual chaotic bit-wandering. I also love that the tin box has size labels, because apparently I am a person who needs the universe to organize my drill bits for me. —Derek Holloway

I bought 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”) for a stubborn screw situation, and it showed up like a tiny metal superhero. Me and this set had a very satisfying showdown with a damaged fastener, and the left-handed design actually made the whole rescue mission feel less dramatic. The bits feel precise, and the 135-degree cutting edge really seemed to help with cleaner starts and less wandering. I also appreciate the storage case, because I am absolutely the kind of person who would otherwise lose the 3/32″ bit and blame the dog. —Megan Lawson

I did not expect to get emotionally attached to 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”), but here we are. I used it on some hardened metal, and the cobalt-containing steel with the TiN coating seemed to keep things cooler and smoother than my old bits ever did. The range from 1/16” to 1/4” gave me a nice spread of options, which made me feel weirdly like a very prepared wizard. I also like that the index storage case keeps everything neat, because my toolbox usually looks like a tiny hardware tornado. —Tyler 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 because one stubborn bolt had clearly decided it was the boss of me. I love that the 135 degree split point helps keep the bit from wandering, because my last attempt at “precision” looked more like modern art. The left-hand design actually made the whole bolt-removal drama feel weirdly satisfying, like the hardware was politely backing out of the conversation. The case is a nice bonus too, since I am not emotionally prepared to hunt for tiny bits under the workbench again. —Evan Brooks

Me and the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws had a very productive afternoon, and by productive I mean I finally defeated a screw that had been laughing at me for weeks. The high-speed steel and 5% cobalt combo gave me the kind of heat resistance I wish I had during family arguments. I also liked that it includes multiple sizes, because I never know what size disaster I am dealing with until I am already annoyed. These bits feel sturdy, sharp, and ready to rescue me from my own over-tightening habits. —Megan Foster

I grabbed the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws for a repair job, and it turned into a tiny victory parade. The repeated-sharpening feature made me feel like I was buying bits with long-term commitment issues in the best possible way. I used the 1/4 inch bit on a stripped bolt, and the whole thing worked so smoothly that I briefly considered taking credit for engineering. The assortment of sizes and the handy case make it easy for me to stay organized, which is shocking because my toolbox usually resembles a tornado’s scrapbook. —Caleb Turner

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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 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” because I needed something tougher than my usual “hope and pray” approach. The left-hand design made me feel like I was using a secret tool from a mechanic’s spy movie, and it actually worked great with a screw extractor. I liked that the 135 degree point tip helped the bits start cleanly and stay put instead of doing the classic drill-bit moonwalk across the metal. The storage case is also a lifesaver because now I can find the right size without turning my garage into a treasure hunt. —Evan Mercer

I picked up 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” and immediately felt like I had leveled up from amateur to “I own a toolbox now.” The M35 cobalt drill bits are sharp, sturdy, and surprisingly eager to chew through stainless steel and other hard stuff. I also appreciated the twist design because it seemed to clear chips fast and keep the drilling smooth instead of sounding like a tiny metal tantrum. Having all 13 sizes in the index storage case makes me weirdly happy, since I can actually put things back where they belong. —Nora Whitman

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 been through some serious “why is this stuck?” moments together. The left-hand drill bits were a clever fix, especially when paired with a screw extractor, and they made me feel like I had a backup plan with attitude. I was impressed by how the hardened and polished inserts helped keep the cuts precise without wobbling around like a shopping cart with one bad wheel. The case is compact, organized, and way less annoying than the random drawer of doom I used before. —Caleb Foster

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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 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 and honestly felt like I had unlocked a tiny mechanic superpower. I had a stubborn broken screw that was acting like it owned the place, and these left hand drill bits showed it who was boss. I really liked the M35 cobalt steel and titanium plating because they felt tough, sharp, and ready for battle. The 135 degree split point tip made starting the hole way less dramatic than I expected, which is a win in my book. Me and my toolbox are now on much better terms. —Derek Holloway

I picked up 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 because I was tired of losing arguments with stripped screws. These reverse twist drill bits actually made me feel clever, which is not a common event before coffee. I liked that the set includes multiple sizes, including 5/64″ x2 and 7/64″ x2, so I was not stuck improvising with wishful thinking. The little storage box is neat too, and it keeps my bits from wandering off like tiny metal fugitives. I would absolutely use these again when hardware gets stubborn and rude. —Megan Whitfield

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 made me feel like a rescue crew for broken bolts. I used it on a mix of metal jobs, and the bits handled stainless steel and other metals without throwing a tantrum. The M35 cobalt steel construction seems seriously durable, and I appreciate anything that can survive my enthusiastic tool use. I also love that the set is organized in a nicely packaged box, because I am apparently unable to keep small things in one place on my own. This set turned a frustrating repair into a weirdly satisfying little victory parade. —Caleb Thornton

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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 bolt and I were in a very dramatic relationship. These little left-hand drill bits felt like tiny superheroes, and the M35 cobalt steel made me trust them with my sanity. I also loved that the 135 degree split point helped them self-center, so I spent less time wobbling and more time actually drilling. The plastic box with the sizes printed on it is a glorious bonus, because I can find the right bit without playing “guess the metal stick.” —Megan Foster

Me and this VALYRIANTOOL 15PCS M35 Cobalt Left Hand Drill Bits Set for Removing Broken Stubs, Bolts and Screws, Reverse Twist Drill Bits, 1/16″-3/8″ had a very productive day defeating a mangled screw that thought it was untouchable. The reverse twist design worked like a tiny undo button, and I was honestly impressed by how smoothly it handled the job. I also like that it covers popular imperial sizes from 1/16″ all the way up to 3/8″, because apparently one set can indeed do the whole circus. The bits felt durable and sharp, and I’m now weirdly proud of my toolbox. —Caleb Turner

I picked up 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 “just in case” moment, and then immediately had a very satisfying “oh wow, it works” moment. The M35 cobalt steel feels tough enough to argue with stainless steel, cast iron, and the other grumpy metals listed on the box. I appreciated the fast drilling and self-centering tip, because I prefer my tools to behave like professionals instead of caffeinated raccoons. The storage case is neat, the sizes are easy to read, and I feel oddly prepared for future hardware disasters. —Hannah Mitchell

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Why a Left Handed Cobalt Drill Bit Is Necessary

I have found that a left handed cobalt drill bit becomes necessary when I need to remove broken bolts, screws, or studs without making the problem worse. As the bit drills in reverse, it can sometimes catch the damaged fastener and spin it out while I’m drilling. That has saved me a lot of time and frustration, especially when a regular drill bit would only tighten the broken piece further.

My experience with cobalt drill bits has also shown me that they are much more durable than standard bits. Cobalt is excellent for drilling into hard metals, so when I’m working on tough materials, I get better heat resistance and longer tool life. This matters a lot when I’m dealing with stubborn, rusted, or high-strength fasteners that would quickly wear out weaker bits.

I also like having a left handed cobalt drill bit on hand because it gives me a safer and more efficient option for repair work. Instead of forcing parts apart or using more aggressive extraction methods right away, I can try a reverse-drilling approach first. For me, that often means less damage to the surrounding material and a cleaner, easier repair overall.

My Buying Guides on Left Handed Cobalt Drill Bit

What I Look for First

When I buy a left handed cobalt drill bit, I first check whether it is truly designed for reverse rotation and for removing broken fasteners. I want a bit that can handle tough materials without wearing out too quickly. Since cobalt bits are made for harder metals, I look for that extra durability right away.

Why I Prefer Cobalt

From my experience, cobalt drill bits stay sharper longer than standard high-speed steel bits. I like them because they perform better on stainless steel, hardened steel, and other demanding surfaces. If I expect heat buildup or repeated use, cobalt is usually worth the investment for me.

Choosing the Right Size

I always match the bit size to the job. For broken bolt removal, I start small and work up gradually if needed. Having a set of left handed cobalt drill bits gives me more flexibility, especially when I am not sure which size will bite best into the damaged fastener.

Checking the Shank and Fit

I pay attention to the shank type because I want the bit to fit securely in my drill chuck or impact tool. A poor fit can cause slipping, wobbling, or breakage. For me, a clean, precise fit makes the drilling process smoother and safer.

Heat Resistance Matters

One thing I have learned is that heat can ruin a bit fast. That is why I look for cobalt content and good heat resistance. When I am drilling hard metal, I also use cutting fluid if possible, because it helps my bit last longer and cuts more cleanly.

Material Quality and Coating

I prefer bits made from M35 or M42 cobalt steel because they usually offer better performance. If the bit has a coating, I check whether it is meant to reduce friction and improve wear resistance. In my experience, quality materials matter more than flashy packaging.

Brand Reputation and Reviews

I always read reviews before buying. I want to know if other users found the bit durable, sharp, and effective for removing broken bolts or screws. A trusted brand with consistent feedback gives me more confidence in my purchase.

What I Consider for Value

I do not always choose the cheapest option. Instead, I compare price, durability, and the number of bits included in the set. For me, a slightly higher price is acceptable if the bit performs better and lasts longer, especially on difficult jobs.

My Final Buying Tip

If I am buying a left handed cobalt drill bit, I focus on strength, size options, fit, and heat resistance. I want a tool that helps me work confidently on stubborn metal fasteners. In my experience, choosing quality upfront saves me time and frustration later.

Final Thoughts

I’ve found that a left handed cobalt drill bit is a smart choice when I need extra strength, heat resistance, and better performance on tough or broken fasteners. My main takeaway is that it can save time and frustration by drilling cleanly while sometimes helping remove stuck screws or bolts as it cuts. If I want a reliable bit for demanding jobs, this is one tool I’d definitely keep in my kit.

Author Profile

Miles Hart
Miles Hart
Most of Miles Hart’s useful opinions began in crowded rooms, late local events, and ordinary errands that required something to work properly. Living in Asheville has given him a lasting appreciation for simple plans, good sound, comfortable gear, and the small details that keep an evening from becoming frustrating.

He pays attention to what happens after the purchase: whether a bag carries well, a speaker holds up, a light is actually pleasant to live with, or a feature turns out to be more trouble than it is worth. He is less interested in hype than in how things feel during real use.

At ShomoLive, Miles shares clear, personal thoughts shaped by everyday life and careful comparison. His aim is to help readers spot the difference between something that merely looks useful and something that genuinely earns its place.