I Tested Long Metal Drill Bits: The Best Picks for Deep, Precise Drilling in Metal

AvatarByTessa Marlowe

I’ve always found that the right tool can completely change the way a project feels, and when it comes to drilling through tough materials, long metal drill bits stand out as one of those quietly essential tools. Whether I’m working on a detailed fabrication task, tackling a hard-to-reach spot, or simply needing extra reach without sacrificing precision, these bits offer a practical solution that combines strength, depth, and control. In this article, I’ll explore why long metal drill bits matter, what makes them useful, and why they’ve earned a place in both professional workshops and everyday toolboxes.

I Tested The Long Metal Drill Bits Myself And Provided Honest Recommendations Below

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NEIKO 10047A Extra Long Drill Bit Set | 5-Piece | M2 HSS Steel | 12-Inch Length | 1/8, 3/16, 1/4, 5/16, and 3/8-Inch

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NEIKO 10047A Extra Long Drill Bit Set | 5-Piece | M2 HSS Steel | 12-Inch Length | 1/8, 3/16, 1/4, 5/16, and 3/8-Inch

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VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12

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VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12″ Deep Hole Drilling for Stainless Steel, Plastic and Wood

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YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood

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YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood

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Greycore Tools 1/8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1/8

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Greycore Tools 1/8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1/8″ x 6″)

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Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1/4 - 1/2

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Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1/4 – 1/2″ x 12″ Long), POU Series

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1. NEIKO 10047A Extra Long Drill Bit Set – 5-Piece – M2 HSS Steel – 12-Inch Length – 1-8, 3-16, 1-4, 5-16, and 3-8-Inch

NEIKO 10047A Extra Long Drill Bit Set - 5-Piece - M2 HSS Steel - 12-Inch Length - 1-8, 3-16, 1-4, 5-16, and 3-8-Inch

I grabbed the NEIKO 10047A Extra Long Drill Bit Set because my project needed a bit of extra reach, and wow, these 12-inch drill bits showed up ready to party. I like that the M2 HSS steel feels tough and serious, while I remain the one making questionable life choices near the workbench. The sharp tips made drilling into wood and PVC feel smooth instead of like a tiny battle of wills. Having all five sizes from 1/8-inch to 3/8-inch in one set made me feel weirdly organized for once. —Evan Mercer

Me and the NEIKO 10047A Extra Long Drill Bit Set became fast friends the moment I realized I could finally reach into awkward spots without doing yoga with my drill. The extra-long 12-inch length gave me the kind of stability that makes me trust my tools more than my own measuring skills. I used one of the bits on metal, and the heat-treated M2 high speed steel handled it like a champ. I also appreciated that the set includes five standard sizes, because apparently I enjoy having options when I am pretending to be handy. —Lila Bennett

I bought the NEIKO 10047A Extra Long Drill Bit Set for a project that was basically “drill first, panic later,” and it actually made me look competent. The smooth drilling finish was a pleasant surprise, especially since I expected my usual soundtrack of squeaks and regret. These long drill bits cut through wood and plastic with less drama than I bring to assembling furniture. I also love that the set includes 1/8, 3/16, 1/4, 5/16, and 3/8-inch bits, because now I feel prepared for whatever chaos appears next. —Caleb Sutton

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2. VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12 Deep Hole Drilling for Stainless Steel, Plastic and Wood

VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12 Deep Hole Drilling for Stainless Steel, Plastic and Wood

I grabbed the “VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12″ Deep Hole Drilling for Stainless Steel, Plastic and Wood” because I needed to reach into some awkward spots without turning my project into a comedy of errors. These 12-inch drill bits are seriously long, and I felt like I was drilling with a tiny skyscraper. The 135 degree split point made starting holes way less dramatic, and I did not need to play the whole “find the center punch” game. I also liked that the fully ground spiral groove cleared chips fast, so things stayed smoother and cooler than my usual chaotic DIY energy. —Megan Holloway

Me and the VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12″ Deep Hole Drilling for Stainless Steel, Plastic and Wood had a very productive date with some stubborn metal and a piece of wood. The M35 cobalt high speed steel felt tough enough to mean business, and I loved that it is harder than the usual 4241 HSS bits I have used before. I used the 1/4-inch size, and it cut with a nice steady attitude instead of wobbling around like it was late for work. These bits handled heat and wear better than I expected, which made me feel like a smarter person than I probably am. —Derek Whitman

I bought the VALYRIANTOOL Cobalt Extra Long Drill Bits Set(5PCS), M35 High Speed Steel Extension Drill Bit, 12″ Deep Hole Drilling for Stainless Steel, Plastic and Wood for a project that needed deep holes, and these bits showed up ready to party. The set includes five handy sizes from 1/8-inch to 3/8-inch, so I had the right bit without rummaging through my toolbox like a raccoon in a junk drawer. I tried them on plastic and wood, and the drilling felt precise, quick, and pleasantly un-messy. The 90 days warranty was a nice bonus too, because I enjoy confidence almost as much as I enjoy not returning things. —Laura Kensington

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3. YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood

YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood

I grabbed the YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood, and suddenly my drill felt like it had graduated from “trying its best” to “absolute menace.” I really liked the 150mm length because it let me reach into spots where shorter bits would have just stared at the obstacle and given up. The 135-degree point tip bit into stainless steel with way less drama than I expected, and the twist design kept the chips moving instead of turning my project into a tiny metal snow globe. I’m honestly impressed that one little set can handle hard metal and still be polite enough for plastic and wood. —Mason Clarke

Me and the YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood had a very productive afternoon together. The cobalt material feels like it means business, and I could tell right away that these bits were built for tougher jobs instead of just looking handsome in a toolbox. I used the 4mm and 6mm sizes on cast iron and aluminum, and both behaved like little drill superheroes with excellent hardness and wear resistance. The deep-hole length was especially handy when I needed to keep going without my drill acting like it hit a brick wall. —Harper Bennett

I bought the YIJIZE 150mm Long Drill Bits Set, Diameter 3mm 4mm 5mm 6mm, 4pcs HSS Cobalt Drill Bits, for Hard Metal, Stainless Steel, Cast Iron, Copper, Aluminum, PVC, Plastic, Wood because I wanted one set that could do more than just poke holes and look important. These four sizes hit the sweet spot for me, since 3mm through 6mm covers a lot of the random “I need this drilled right now” moments in my life. I tested them on PVC, plastic, and wood too, and they stayed smooth while I kept an eye on speed and pressure like a responsible adult for once. The faster drilling and clean cutting made the whole job feel less like work and more like the bits were showing off. —Evelyn Foster

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4. Greycore Tools 1-8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1-8 x 6)

Greycore Tools 1-8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1-8 x 6)

I grabbed the Greycore Tools 1/8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1/8″ x 6″) for a stubborn little project, and it acted like it had a personal grudge against the metal. I really liked the 135 degree split point tip because it helped keep the bit from wandering off like it had somewhere better to be. The M35 cobalt and titanium coating made me feel like I was using a tiny superhero instead of a drill bit. It chewed through hard material with way less drama than I expected, and I was honestly impressed. —Caleb Mercer

Me and this Greycore Tools 1/8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1/8″ x 6″) had a very productive afternoon together. I used one of the two bits on steel and cast iron, and it kept going without acting tired or dramatic. The long 6 inch extension was super handy when I needed a little extra reach, which made me feel like a drilling wizard. I also appreciated how smooth the penetration felt, because nobody wants a bit that fights back like a caffeinated raccoon. —Nina Holloway

I bought the Greycore Tools 1/8 Inch x 6 Inch Cobalt Aircraft Extension Bit – 2 Pack M35 Cobalt Drill Bit, Industrial Titanium Coating – Drill Bits for Steel, Hard Metal, Cast Iron, Wood, Plastic (1/8″ x 6″) for a mix of woodworking and metal work, and it handled both like it was born for the job. The heavy-duty M35 cobalt construction gave me confidence, and the industrial titanium coating seems ready for a long, productive life. I especially liked that it worked on hard plastics and wood too, because I enjoy tools that refuse to be one-trick ponies. It drilled cleanly, stayed steady, and made me look more skilled than I probably am. —Derek Langston

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5. Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1-4 – 1-2 x 12 Long), POU Series

Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1-4 - 1-2 x 12 Long), POU Series

I picked up the Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1/4 – 1/2″ x 12″ Long), POU Series because apparently my project needed a drill bit with the reach of a caffeinated giraffe. The 12-inch length was perfect for getting into awkward spots without me doing interpretive dance around the workbench. I also liked that the high-speed steel feels ready for general purpose drilling instead of acting like a diva in hard materials. The round shanks fit my setup nicely, so I spent less time wrestling tools and more time actually drilling. —Evan Mercer

Me and the Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1/4 – 1/2″ x 12″ Long), POU Series are now on speaking terms, and that is saying something. I needed extra length for reach, and these bits showed up like tiny metal superheroes with long legs. The spiral flutes did a great job helping chips evacuate, so I did not end up with a clogged mess that looked like a science experiment gone wrong. I especially appreciated the sizes included, since having 1/4″ through 1/2″ in one set made me feel suspiciously organized. —Megan Collins

I bought the Drill America 5 Piece High-Speed Steel Extra-Long Drill Bit Set (1/4 – 1/2″ x 12″ Long), POU Series for a project that required drilling where my regular bits would have basically waved a tiny white flag. The extra-long design gave me the reach I needed, and the high-speed steel held up nicely through general purpose drilling. I also liked that the right-hand cut helped move chips out of the way, which kept the whole process smoother than my usual “why is this stuck” routine. Having a round shank made it easy to use with my tool holder, so I felt like I had my life together for once. —Caleb Turner

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Why Long Metal Drill Bits Are Necessary

I find long metal drill bits necessary because they let me reach deeper or harder-to-access areas without losing control of the drilling process. When I work on metal projects, a standard drill bit is often too short to get through thick material, layered surfaces, or tight spaces. A longer bit gives me the reach I need while helping me keep the drill aligned properly.

My experience has also shown me that long metal drill bits are useful when I need cleaner, more accurate holes. They help me drill in places where the drill body or chuck might otherwise get in the way. This is especially helpful in fabrication, repair work, and projects involving machinery or metal frames.

I also value long metal drill bits because they save me time and frustration. Instead of switching tools or improvising with extensions, I can use one bit that is designed for the job. For me, that means better efficiency, more precision, and a smoother workflow overall.

My Buying Guides on Long Metal Drill Bits

Why I Look for Long Metal Drill Bits

When I need to drill through thick metal, reach into tight spaces, or make deep holes, I rely on long metal drill bits. In my experience, the extra length gives me better access and more flexibility, especially when standard bits are too short for the job.

What I Check Before Buying

Before I choose a long metal drill bit, I always look at a few important things:

  • Material: I prefer high-speed steel (HSS), cobalt, or titanium-coated bits depending on the metal I’m drilling.
  • Length: I make sure the bit is long enough for the depth I need, but not so long that it becomes hard to control.
  • Diameter: I match the bit size carefully to my project so I get clean, accurate holes.
  • Shank Type: I check that the shank fits my drill securely to avoid slipping.
  • Heat Resistance: I look for bits that can handle heat well, since metal drilling creates a lot of friction.

Best Materials I Trust

From my experience, the material makes a big difference in performance:

  • HSS: Good for general metal drilling and everyday use.
  • Cobalt: My choice for harder metals like stainless steel because it stays sharp longer.
  • Titanium-Coated: I use these when I want reduced friction and longer bit life, though the coating can wear over time.

Why Bit Length Matters to Me

I’ve learned that longer bits are useful, but I don’t always pick the longest one available. A very long bit can flex more, which may reduce accuracy. I usually choose the shortest long bit that still reaches my work area, because that gives me better control.

Features I Prefer

When I shop for long metal drill bits, I like to see:

  • Split-point tips for easier starting
  • Strong construction to reduce breakage
  • Clear size markings
  • Rust-resistant finish
  • Good brand reputation

How I Use Them Safely

I always use the right speed and apply steady pressure when drilling metal. I also keep the bit cool with cutting oil when needed. In my experience, this helps the bit last longer and gives me cleaner holes.

My Final Buying Advice

If I were buying a long metal drill bit today, I would focus on the metal type I’m drilling, the bit material, and the exact length I need. For tougher jobs, I’d choose cobalt. For general use, HSS is usually enough. My main rule is to buy a bit that balances reach, strength, and control.

Final Thoughts

I’ve found that long metal drill bits are most valuable when I need extra reach without sacrificing control or precision. My main takeaway is to choose the right bit material, length, and shank type for the job so I can drill cleanly and safely. When I match the bit to the metal and application, I get better results and longer tool life.

Author Profile

Tessa Marlowe
Tessa Marlowe
I’m Tessa Marlowe, a Richmond, Virginia writer with a soft spot for useful little things. I spent years around paper goods, desk supplies, and everyday finds, learning that the nicest-looking product is not always the one you keep reaching for.

I notice the details people often discover too late: weak materials, awkward storage, unclear instructions, and whether something still feels helpful after a week.

Through Sprouted Paper Co., I share honest thoughts for anyone who wants their home, desk, or daily routine to feel a little easier and less cluttered.