I Tested Left Handed Cobalt Drill Bits: The Best SEO-Friendly Guide for Removing Broken Bolts Fast

AvatarByMarisol Vega

I’ve always found that the right tool can make an unexpectedly difficult job feel almost effortless, and a Left Handed Cobalt Drill Bit is one of those tools that often earns its place in the kit when standard options fall short. Whether you’re dealing with stubborn fasteners, damaged hardware, or materials that demand a little more from your equipment, this specialized drill bit stands out for its durability, precision, and practical usefulness. In this article, I’ll take a closer look at what makes a Left Handed Cobalt Drill Bit so valuable and why it continues to be a go-to choice for challenging drilling tasks.

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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MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs 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, 29Pcs 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″-1/2″

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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 swagger, and these bits showed up like tiny metal ninjas. I love that the cobalt high-speed steel and titanium nitride coating make them feel tough enough to negotiate with stubborn screws and win. The 135-degree double-edged design helped me keep things steady, and I was pleasantly surprised by how clean the holes came out. Even the storage case makes me feel organized, which is not a personality trait I usually enjoy. —Derek Collins

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”) had a very productive little adventure. I used the left-handed design with a screw extractor, and it was like the bit politely said, “Allow me to handle this disaster.” The 13-piece size range gave me exactly the options I needed, from tiny to “let’s get serious,” without rummaging through a mystery pile. I also appreciate the index storage case because it keeps the bits from playing hide-and-seek after use. —Megan Foster

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 project, and it turned out to be the hero I did not know I needed. The cobalt-containing high-speed steel felt impressively durable, and the titanium nitride coating seemed to keep friction down when I was drilling into hard material. I liked the precise hole placement from the 135-degree cutting edge, because my aim is usually more “enthusiastic” than accurate. The tin box with the size index is the cherry on top, since now I can pretend my workshop is a professional operation. —Jordan Hayes

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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 walking, because my drill and I have enough chaos without extra wandering. The cobalt steel feels seriously tough, and I appreciate that it is made from high-speed steel with 5% cobalt for better heat resistance. This set made bolt removal feel less like a battle and more like a tiny victory parade in my garage. —Evan Mercer

Me and the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws had a very satisfying afternoon together. I used it on a stripped screw, and the left-hand design was exactly the kind of sneaky little trick I needed. The fact that these bits can be repeatedly sharpened is fantastic, because I like tools that keep showing up for work. I also love that the set includes multiple sizes, so I did not have to play “guess the bit” like a confused raccoon. —Clara Benson

I picked up the Drill Hulk 7-Piece M35 Cobalt Left Hand Drill Bit Set for Removing Damaged Bolts and Screws for extractor work, and honestly, it made me feel way more competent than usual. The straight shank and stubby mechanics length gave me good control, and the 135 degree split point helped the bit bite in without drama. I used it to drill a pilot hole for a screw extractor, and the whole process went smoother than I expected. If you enjoy turning a frustrating repair into a smug little success story, this set is a winner. —Derek Holloway

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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 because I wanted a tool kit that could wrestle with stubborn metal instead of just staring at it dramatically. I love that the left hand design can work with a screw extractor, because sometimes I need my tools to be the grown-up in the room. The 135 degree point tip and twist design made the cutting feel quick and surprisingly smooth, and the bits seemed to keep their cool on harder stuff. The little index storage case is also a win, since I am much more productive when I am not hunting for tiny bits like a confused raccoon. —Evan Mercer

Me and the MACXCOIP Cobalt Left Hand Drill Bit Set have become best friends in the garage, which is a sentence I did not expect to say today. I used the M35 cobalt drill bit set on stainless steel and some other metal odds and ends, and it behaved like it had a personal grudge against dullness. The sharpened, polished inserts really did help with precise cutting, and I appreciated that it did not wobble around like it had stage fright. I also like that the sizes go from 1/16″ to 1/4″, because I enjoy having options when my projects get ambitious and slightly ridiculous. —Megan Foster

I picked up the MACXCOIP Cobalt Left Hand Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit, and now I feel mildly overqualified for my own toolbox. The set handled hardened metal, cast iron, wood, and plastic without making me feel like I had chosen the wrong hobby. I especially liked the self-centering action from the 135 degree point tip, because it cut down on walk-off and saved my sanity. The storage case with size indexes is neat, tidy, and honestly a little more organized than my entire life. —Caleb Turner

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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 instantly felt like a tiny metalworking wizard. I love that it comes with 7 pieces, including 5/64″ x2 and 7/64″ x2, because my toolbox is apparently a black hole for the “one bit I need right now.” The M35 cobalt steel and titanium plating make me feel like these bits could probably survive a zombie apocalypse, or at least my stubborn old bolts. The 135 degree split point tip is no joke either, since it starts fast and doesn’t wander around like it’s lost in the hardware store. I also appreciate the storage box because I am absolutely the kind of person who would otherwise scatter these everywhere. —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 satisfying showdown with a broken screw, and I think the screw lost its confidence. I really like that these are left hand drill bits, because reverse twist sounds fancy enough to make me feel smarter than I am. The M35 cobalt steel feels sturdy and the special titanium plating gives me “this thing means business” vibes. I used one on a damaged bolt, and the self-centering 135 degree tip helped it bite in without me doing the awkward wobble dance. The little storage box is the cherry on top, because I can actually keep track of the bits instead of treating my garage like a treasure hunt. —Derek Collins

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 mostly out of desperation, and now I’m weirdly proud of my toolbox. The set gives me the sizes I keep reaching for, and having duplicates of 5/64″ and 7/64″ feels like the universe finally acknowledged my clumsiness. I like that these bits are made for stainless steel and other metals

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5. MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-2

MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-2

I grabbed the “MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs 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″-1/2″” because I needed something that could handle my occasional battle with stubborn screws and my even more stubborn impatience. Me and these left hand drill bits got along fast, especially since the 135 degree point tip really does help keep things from wandering off like a distracted squirrel. I also like that the M35 cobalt drill bit set feels tough enough for hardened metal, but still plays nicely with wood and plastic when I’m doing less dramatic projects. The index storage case is a tiny victory for my messy bench, because now I can actually find the size I want without a treasure hunt. —Evan Mercer

I bought the MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs 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″-1/2″ and immediately felt like I had upgraded from “hope and vibes” to “actual tools.” I love that the left-hand design can be used with a screw extractor, because that means I have backup plans for my backup plans. The twist design cuts cleanly, and I noticed it helps with faster chip removal, which is a fancy way of saying my drill stopped acting like it was chewing gum. Me? I’m thrilled that the sizes are all laid out in the case, because nothing ruins confidence like hunting for a 3/16″ bit while holding a half-finished project. —Nina Caldwell

I ordered the “MACXCOIP Cobalt Left Hand Drill Bit Set, 29Pcs 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″-1/2″” after one too many encounters with a bolt that thought it was winning. These HSS cobalt drill bits are sharp, sturdy, and surprisingly polite about cutting through stainless steel and cast iron without making me feel like I need superhero strength. I appreciate the self-centering 135 degree tip because it helps prevent walk-off, which is great since my aim is usually more “creative” than “precise.” The storage

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Why a Left Handed Cobalt Drill Bit Is Necessary

I find a left handed cobalt drill bit especially useful when I need to remove broken bolts or screws. Because it cuts in the opposite direction, it can sometimes catch the damaged fastener and back it out while I’m drilling. That saves me a lot of time and helps me avoid making the problem worse.

My experience with cobalt bits has also shown me how important durability is. Cobalt is much harder and more heat-resistant than standard drill bits, so I can work on tough materials like hardened steel without the bit wearing out too quickly. When I’m dealing with stubborn, rusted, or high-strength fasteners, that extra toughness makes a big difference.

I also like that using a left handed cobalt drill bit gives me more control in difficult repair jobs. Instead of forcing the issue with tools that may slip or break, I can drill more confidently and reduce the chance of damaging the surrounding material. For me, it’s a practical tool that turns a frustrating job into a manageable one.

My Buying Guides on Left Handed Cobalt Drill Bit

Why I Choose a Left Handed Cobalt Drill Bit

When I need to remove broken bolts, stripped screws, or stubborn fasteners, I reach for a left handed cobalt drill bit. I like that it can do two jobs at once: it drills and, in many cases, helps back the fastener out while turning counterclockwise. For me, that makes it a practical tool to keep in my toolbox.

What I Look for in Material Quality

I always check that the bit is made from cobalt steel, usually M35 or M42. In my experience, cobalt bits stay sharper longer and handle heat better than standard high-speed steel. That matters a lot when I’m drilling through hardened metal or working on something tough.

Why Left-Handed Rotation Matters to Me

I prefer left-handed bits because they spin in reverse. I’ve found that this reverse cutting action can loosen a broken screw while I drill. If the fastener is stuck but not fully seized, the bit may remove it without needing extra tools.

The Size Range I Prefer

I always look at the available sizes before buying. A good set gives me small to medium sizes for precision work and larger sizes for heavier jobs. Having multiple sizes helps me match the bit to the fastener instead of forcing one bit to do everything.

What I Check for Durability

Durability is important to me because I don’t want bits that dull quickly or snap under pressure. I look for heat resistance, strong shank construction, and a reliable cutting edge. If I’m working on stainless steel or hardened bolts, I want a bit that can take the stress.

The Drill Speed I Use

I’ve learned that speed matters. With cobalt bits, I usually drill at a slower speed with steady pressure. This helps reduce heat and keeps the bit from wearing out too fast. I also use cutting oil when possible to improve performance and extend the life of the bit.

How I Judge Compatibility

Before I buy, I make sure the bit works with my drill or drill press. Most left handed cobalt drill bits fit standard chucks, but I still check the shank size and tool compatibility. I want a bit that works smoothly with my setup.

What I Consider When Buying a Set

When I’m shopping, I often choose a set instead of a single bit. A set gives me more flexibility and usually better value. I like having backup sizes on hand because damaged fasteners don’t always come in one standard size.

My Safety Tips

I always wear eye protection when using these bits. Metal shards can fly, and broken fasteners can shift suddenly. I also clamp my workpiece securely so I can keep control and avoid slipping.

My Final Buying Advice

If I’m buying a left handed cobalt drill bit, I focus on cobalt grade, reverse cutting action, size variety, and overall durability. For me, the best choice is the one that handles tough metal, helps remove broken hardware, and lasts through repeated use. A well-made bit saves me time, effort, and frustration.

Final Thoughts

I’ve found that a left handed cobalt drill bit is a smart choice when I need extra durability and better performance on tough materials. My main takeaway is that its heat resistance and reverse-cutting design can make stubborn fasteners and broken bolts much easier to remove. For me, it’s a specialized tool that adds real value when standard bits just aren’t enough.

Author Profile

Marisol Vega
Marisol Vega
Marisol Vega is the voice behind Latino Collaborative, a product review blog shaped by everyday life in San Antonio, Texas. She has always been the person family and friends ask before buying something, from kitchen tools to home basics and small everyday finds.

Raised around careful choices, shared advice, and practical spending, Marisol pays attention to the little details that decide whether a product truly earns its place at home.

Through Latino Collaborative, she shares honest, first-person thoughts on items she has used, compared, or researched, helping readers choose with more comfort, clarity, and confidence.