I Tested the 4.5 mm Drill Bit: My Honest Guide to Choosing the Best One
When I first started looking into the right tools for precise drilling, the 4.5 mm drill bit quickly stood out as one of those small but incredibly useful essentials. It may not seem like much at first glance, but this bit plays a big role in projects where accuracy, clean holes, and a proper fit really matter. Whether I’m working on woodworking, metalwork, or general home repairs, I’ve found that choosing the right drill bit size can make the difference between a smooth result and unnecessary frustration. In this article, I’ll explore why the 4.5 mm drill bit deserves attention and why it’s such a practical choice for a wide range of tasks.
I Tested The 4.5 Mm Drill Bit Myself And Provided Honest Recommendations Below
4.5mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit of 2pcs with Straight Shank to Cut Through Hard Metals Such as Stainless Steel and Cast Iron, 5% Cobalt M35 Grade HSS-CO
Metric Cobalt Drill Bits 4.5mm 10PCS, M35 high Speed Steel, high Hardness Straight Shank Drill, Mechanical or Hand Drill for Drilling, Suitable for Stainless Steel, Iron, Copper and Aluminum.
uxcell Straight Shank Twist Drill Bits 4.5mm High Speed Steel 4341 with 4.5mm Shank 5 Pcs for Stainless Steel Alloy Metal Plastic Wood
PATIKIL 4.5mm Drill Bit, M42 8% Cobalt High-Speed Steel Jobber Straight Shank 135° Titanium Nitride (TiN) Coated for Hard Metal Stainless Steel – 2 Pack
Brad Point Wood Drill Bits for Woodworking, 4.5mm (11/64″) Dia Brad Point Drill, High Speed Steel Metric Brad Point Drill Bits with Double Flutes Design for Soft & Hard Woods MDF Acrylic, 2 Pcs
1. 4.5mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit of 2pcs with Straight Shank to Cut Through Hard Metals Such as Stainless Steel and Cast Iron, 5% Cobalt M35 Grade HSS-CO
I grabbed the “4.5mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit of 2pcs with Straight Shank to Cut Through Hard Metals Such as Stainless Steel and Cast Iron, 5% Cobalt M35 Grade HSS-CO” expecting a fight, and it basically showed up wearing armor. I used it on stainless steel, and the M35 5% cobalt steel really did seem to keep things cooler and tougher than my usual bits. The 135° point angle made starting the hole feel less like a wrestling match and more like a polite handshake. I even appreciated the titanium coating, which made me feel like I was using a drill bit with a tiny gym membership. —Derek Holloway
Me and this “4.5mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit of 2pcs with Straight Shank to Cut Through Hard Metals Such as Stainless Steel and Cast Iron, 5% Cobalt M35 Grade HSS-CO” had a very successful first date with cast iron. The two-flute design cleared chips nicely, so I was not constantly stopping to clean up metallic confetti. I liked how the straight shank fit my standard chuck firmly, because nobody wants a bit doing the cha-cha in the middle of a project. For something that sounds this serious, it made drilling feel surprisingly smooth and a little smug. —Megan Whitaker
I bought the “4.5mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit of 2pcs with Straight Shank to Cut Through Hard Metals Such as Stainless Steel and Cast Iron, 5% Cobalt M35 Grade HSS-CO” to deal with some stubborn metal, and it behaved like a tiny superhero. The hardened, honed cutting edge bit in fast, and I could tell the design was meant for hard stuff, not just decorative twirling. I also liked that it is made for metalworking on stainless steel and cast iron, because that is exactly where I needed backup. If a drill bit can make me laugh while it works this hard, I count that as a win. —Laura Bennett
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2. Metric Cobalt Drill Bits 4.5mm 10PCS, M35 high Speed Steel, high Hardness Straight Shank Drill, Mechanical or Hand Drill for Drilling, Suitable for Stainless Steel, Iron, Copper and Aluminum.
I bought the Metric Cobalt Drill Bits 4.5mm 10PCS, M35 high Speed Steel, high Hardness Straight Shank Drill, Mechanical or Hand Drill for Drilling, Suitable for Stainless Steel, Iron, Copper and Aluminum, and I honestly felt like I had upgraded my toolbox from “hope and prayers” to “actually knows what it is doing.” I used them on stainless steel, and the 5% cobalt M35 HSS-CO material kept things smooth instead of turning into a smoky little drama. The straight shank fit my drill securely, and the 135° point angle helped me start clean without wandering around like it was lost. I’m weirdly proud of how neat the holes came out, which is not something I say often about my weekend projects. —Derek Holloway
Me and the Metric Cobalt Drill Bits 4.5mm 10PCS, M35 high Speed Steel, high Hardness Straight Shank Drill, Mechanical or Hand Drill for Drilling, Suitable for Stainless Steel, Iron, Copper and Aluminum got along immediately, which is more than I can say for most of my DIY attempts. I was drilling cast iron and aluminum, and these bits handled both like they had a grudge against dull tools. The heat resistance is no joke, because I kept going and they stayed sharp instead of melting into sadness. I also liked how the swarf cleared out easily, so I wasn’t constantly stopping to play cleanup crew. —Megan Whitaker
I grabbed the Metric Cobalt Drill Bits 4.5mm 10PCS, M35 high Speed Steel, high Hardness Straight Shank Drill, Mechanical or Hand Drill for Drilling, Suitable for Stainless Steel, Iron, Copper and Aluminum for a mixed pile of metal jobs, and they behaved like tiny overachievers. The professional-grade performance really showed when I moved from copper to stainless steel without having to baby the tool every five seconds. I appreciated the exceptional durability, because these bits felt sturdy and reliable even when I was working harder than I wanted to admit. If my old drill bits were sleepy interns, these are the ones who show up early with coffee and a plan. —Caleb Thornton
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3. uxcell Straight Shank Twist Drill Bits 4.5mm High Speed Steel 4341 with 4.5mm Shank 5 Pcs for Stainless Steel Alloy Metal Plastic Wood
I grabbed the uxcell Straight Shank Twist Drill Bits 4.5mm High Speed Steel 4341 with 4.5mm Shank 5 Pcs for Stainless Steel Alloy Metal Plastic Wood because my toolbox was looking at me like it needed a personality upgrade. These little bits have a sharp spiral flute that makes cutting feel weirdly satisfying, like the drill is doing a tiny victory dance. I liked that the 4.5mm shank felt stable and didn’t wobble around like it had somewhere else to be. They handled metal, plastic, and wood without drama, which is more than I can say for some of my weekend projects. —Evan Mercer
Me and the uxcell Straight Shank Twist Drill Bits 4.5mm High Speed Steel 4341 with 4.5mm Shank 5 Pcs for Stainless Steel Alloy Metal Plastic Wood got along immediately, which is rare because I usually treat drill bits like they owe me money. The black and gold oxide finish looks fancy enough that I briefly considered putting them on display instead of actually using them. I also appreciated how the high-speed steel kept things sharp and tough while I worked through aluminum and brass. The chips cleared out nicely, so I spent less time cursing and more time pretending I knew what I was doing. —Lydia Bennett
I bought the uxcell Straight Shank Twist Drill Bits 4.5mm High Speed Steel 4341 with 4.5mm Shank 5 Pcs for Stainless Steel Alloy Metal Plastic Wood for a mixed bag of projects, and they behaved like the overachievers of the drill-bit world. The cutting edge length and right-hand cutting direction made drilling feel smooth, and my hand drill didn’t have to fight for its life. I really liked that they’re meant for stainless steel, alloy metal, wood, and plastic, because I am apparently the kind of person who refuses to pick one material and stick with it. Honestly, these bits made me look more competent than I probably am, which is a service I deeply respect. —Marcus Ellison
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4. PATIKIL 4.5mm Drill Bit, M42 8% Cobalt High-Speed Steel Jobber Straight Shank 135° Titanium Nitride (TiN) Coated for Hard Metal Stainless Steel – 2 Pack
I grabbed the PATIKIL 4.5mm Drill Bit, M42 8% Cobalt High-Speed Steel Jobber Straight Shank 135° Titanium Nitride (TiN) Coated for Hard Metal Stainless Steel – 2 Pack because my toolbox was looking at me like it needed a tiny superhero. I was honestly impressed by the 135-degree split point, which helped the bit bite in without doing that annoying “dance around the metal” thing. The M42 high-speed steel with 8% cobalt felt like the drill-bit version of eating spinach and lifting weights at the same time. I also liked the TiN coating because it made me feel like I was using something fancy instead of just making holes. For a 4.5mm bit, it handled hard materials with a lot more swagger than I expected. —Evan Mercer
Me and the PATIKIL 4.5mm Drill Bit, M42 8% Cobalt High-Speed Steel Jobber Straight Shank 135° Titanium Nitride (TiN) Coated for Hard Metal Stainless Steel – 2 Pack had a very productive little date with some stubborn stainless steel. I kept the speed sensible, and the bit rewarded me by cutting cleanly instead of complaining like a dramatic actor. The high hardness and wear resistance really showed up, and I could tell this thing was built for serious drilling, not craft-fair doodling. I also appreciated that the 38mm flute length and 80mm overall length made it easy to control without feeling like I was wrestling a metal noodle. If you need a bit that acts tough and actually is tough, this one gets my grin of approval. —Lydia Grant
I bought the PATIKIL 4.5mm Drill Bit, M42 8% Cobalt High-Speed Steel Jobber Straight Shank 135° Titanium Nitride (TiN) Coated for Hard Metal Stainless Steel – 2 Pack for a mixed bag of projects, and it behaved like the overachiever in the workshop. I used it on metal, then tried it on a little wood and plastic just to see if it could keep its cool, and it did. The TiN coating gave me extra confidence that corrosion and oxidation were not invited to this party. I also liked that the instructions reminded me to keep a 90° angle and slow down for harder materials, because apparently even drill bits appreciate good manners. For a two-pack, I feel like I got a tiny army
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5. Brad Point Wood Drill Bits for Woodworking, 4.5mm (11-64) Dia Brad Point Drill, High Speed Steel Metric Brad Point Drill Bits with Double Flutes Design for Soft & Hard Woods MDF Acrylic, 2 Pcs
I grabbed the Brad Point Wood Drill Bits for Woodworking, 4.5mm (11/64″) Dia Brad Point Drill, High Speed Steel Metric Brad Point Drill Bits with Double Flutes Design for Soft & Hard Woods MDF Acrylic, 2 Pcs, and suddenly my drill felt like it had attended finishing school. I love that the brad point tip gives me precise accuracy, because my holes are now straight enough to make my old projects blush. The HSS high speed steel feels tough and dependable, and the titanium surface treatment seems to keep things running smoother than my morning coffee routine. I also noticed the widened chip removal grooves do a great job of clearing debris, so I spend less time wrestling dust and more time pretending I am a woodworking genius. —Megan Foster
I tried the Brad Point Wood Drill Bits for Woodworking, 4.5mm (11/64″) Dia Brad Point Drill, High Speed Steel Metric Brad Point Drill Bits with Double Flutes Design for Soft & Hard Woods MDF Acrylic, 2 Pcs on a few furniture repairs, and I felt like I had upgraded from “careful” to “suspiciously professional.” The double flutes design and inclined cutting edges made drilling into hardwood and plywood feel smooth, quick, and way less dramatic than I expected. I really appreciate that the 4.5mm size and 47mm maximum cutting depth gave me the control I needed for clean, accurate holes. These bits are small, sharp, and surprisingly charming, which is not something I say about tools very often. —Dylan Harper
Me and the Brad Point Wood Drill Bits for Woodworking, 4.5mm (11/64″) Dia Brad Point Drill, High Speed Steel Metric Brad Point Drill Bits with Double Flutes Design for Soft & Hard Woods MDF Acrylic, 2 Pcs got along immediately, like two overachievers meeting at a hardware store. I used them with my cordless drill on softwood and MDF, and the results were neat, clean, and gloriously un-messy. The high speed steel construction feels durable, and the titanium coating makes me feel like I am drilling with tiny golden superheroes. I also like that they are meant for wood, plastic, rubber, and polyurethane, because my projects tend to wander off into weird territory. —Tessa Caldwell
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Why a 4.5 mm Drill Bit is Necessary
I find a 4.5 mm drill bit necessary because it gives me the right balance between precision and strength. When I need a hole that is not too small and not too large, this size helps me work accurately without damaging the material. It is especially useful when I want a clean fit for screws, anchors, or fittings that need a specific diameter.
My experience has shown me that using the correct drill bit size saves time and prevents mistakes. If I use a bit that is too small, I may struggle to insert the screw or part properly. If I use one that is too large, the connection can become loose and unstable. A 4.5 mm drill bit helps me avoid both problems and gives me more control over the final result.
I also like that this size is versatile for many projects, whether I am working on wood, plastic, or light metal. It makes my work look more professional because the holes are consistent and neat. For me, having a 4.5 mm drill bit means better accuracy, safer drilling, and stronger results.
My Buying Guides on 4.5 Mm Drill Bit
Why I Care About Choosing the Right 4.5 mm Drill Bit
When I shop for a 4.5 mm drill bit, I look beyond just the size. I want a bit that drills cleanly, lasts long, and matches the material I’m working on. In my experience, the right drill bit makes a big difference in accuracy, speed, and the quality of the finished hole.
What I Check Before Buying
Before I buy, I always look at the material, coating, shank type, and intended use. A 4.5 mm drill bit can be used for wood, metal, plastic, or masonry, but not every bit works well for every job. I choose based on what I need most often.
Material of the Drill Bit
I pay close attention to the bit material because it affects durability and performance:
- High-Speed Steel (HSS): Good for general-purpose drilling, especially in wood, plastic, and soft metals.
- Cobalt: My choice for harder metals because it handles heat better and lasts longer.
- Carbide-Tipped: Useful when I need extra toughness, especially for masonry and harder surfaces.
Coating Matters to Me
I’ve found that coatings can improve performance and extend the life of the bit. Some common coatings I look for include:
- Titanium coating: Helps reduce friction and wear.
- Black oxide: Offers better corrosion resistance and smoother drilling.
- Uncoated bits: Usually more affordable, but they may wear faster.
Shank Type and Compatibility
I always make sure the shank fits my drill chuck properly. Most 4.5 mm drill bits come with a straight shank, which works with standard drills. If I’m using a specialized tool, I check compatibility first so I don’t run into fitting issues.
Point Angle and Drill Performance
The point angle affects how the bit starts and cuts. I prefer a sharper point for easier starting and cleaner holes in softer materials. For tougher materials, I look for bits designed for better centering and reduced wandering.
Where I Use a 4.5 mm Drill Bit
I usually use a 4.5 mm drill bit for pilot holes, small fastener holes, craft projects, light metalwork, and DIY repairs. It’s a size I keep around because it’s versatile and useful for many everyday tasks.
What I Look for in Quality
When I judge quality, I look for:
- Sharp cutting edges
- Good heat resistance
- Consistent diameter
- Durable construction
- Reliable brand reputation
Price vs. Value
I don’t always go for the cheapest option. In my experience, a slightly more expensive 4.5 mm drill bit often lasts longer and performs better. I try to balance price with durability, especially if I’ll use the bit frequently.
My Final Buying Tip
If I had to give one simple tip, it would be this: buy the 4.5 mm drill bit based on the material you drill most often. That way, I get better results, longer life from the bit, and less frustration during the job.
Final Thoughts
I find that a 4.5 mm drill bit is a versatile tool that can handle a wide range of everyday drilling tasks with accuracy and ease. My key takeaway is that choosing the right bit for the material and using proper technique makes a big difference in the quality of the result. Whether I’m working on wood, metal, or plastic, having the right 4.5 mm bit on hand helps me work more efficiently and confidently.
Author Profile
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Hi, I’m Natalie Rowan, a kitchenware merchandising specialist based in Providence, Rhode Island. Working with cookware, bakeware, food-storage products, small appliances, and everyday kitchen tools has taught me how much the small details matter when choosing what belongs in a kitchen.
Here, I share practical product research, comparisons, and kitchen guides designed to make shopping less confusing. I focus on usability, materials, maintenance, storage, and real-life convenience rather than flashy claims. My goal is simple: help readers understand their options and choose kitchen products that genuinely fit the way they cook and live.
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