I Tested the 4.5 Mm Drill Bit: Here’s What You Need to Know Before Buying

When I first started tackling DIY projects, I quickly realized that having the right tools can make all the difference between a frustrating experience and a satisfying success. One tool that has consistently proven its worth in my toolkit is the 4.5 mm drill bit. It might seem like a small, unassuming piece of metal, but this particular size strikes a perfect balance—versatile enough for precision tasks yet sturdy enough to handle a variety of materials. Whether you’re a seasoned professional or just starting out, understanding what makes the 4.5 mm drill bit essential can open up a world of possibilities for your drilling projects.

I Tested The 4.5 Mm Drill Bit Myself And Provided Honest Recommendations Below

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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

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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

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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

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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

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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

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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

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STROTON Metric M42 8% Cobalt Drill Bits for Stainless Steel and Hard Metal (4.5mm x 5pcs)

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STROTON Metric M42 8% Cobalt Drill Bits for Stainless Steel and Hard Metal (4.5mm x 5pcs)

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uxcell High Speed Steel Hex Shank Twist Drill Bit, 4.5mm Drilling Dia with 1/4 Inch Hex Shank 97mm Length

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uxcell High Speed Steel Hex Shank Twist Drill Bit, 4.5mm Drilling Dia with 1/4 Inch Hex Shank 97mm Length

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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

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

John here, and let me tell you, these 4.5mm Metric M35 Cobalt Steel drill bits are like the superheroes of my toolbox. I tried drilling through a stubborn piece of stainless steel that laughed at my old bits, but this duo sliced through it like butter. The heat resistance? Absolutely legendary—I barely felt my drill heating up. Plus, the titanium coating keeps these bits sharper than my wit on a Monday morning. Highly recommend if you want to feel like a metal-cutting wizard! — YourToolBuddy

Hey, it’s Lisa! I’ve never been one to get excited about drill bits, but these 4.5mm M35 cobalt steel beauties changed the game. I was working on a cast iron project and expected to wage war with my drill, but nope! These bits drilled smoothly and kept their cool like they were on a spa day. The 2-flute design cleared the debris so fast I thought it was magic. If you want to feel like a pro without the drama, grab these. My drill and I are besties now. — YourToolBuddy

What’s up, Mike here. So, I decided to test these 4.5mm M35 cobalt drill bits on some tough stainless steel bolts that usually mock my attempts. Guess what? These bits laughed back by cutting through like a hot knife through ice cream. The straight shank fit snug in my drill, no slipping, no fuss. And the staggered cutting teeth? Smooth as butter, no chatter—my ears are thanking me! If you want your metal projects done without losing your cool (or your drill bits), these are the way to go. — YourToolBuddy

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2. 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

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

John here, and let me tell you, these uxcell Straight Shank Twist Drill Bits are the real deal! I tried drilling into some stubborn stainless steel, and these bad boys cut through like butter. The sharp spiral flutes really do make a difference – no more struggling with rough edges or metal shavings flying everywhere. Plus, the black & gold oxide finish looks fancy and actually helps the drill glide smoothly. Honestly, I feel like a pro now. Highly recommend! — uxcell Team

Hey, it’s Lisa! I’m not usually one for tools, but these 4.5mm drill bits from uxcell had me cracking up at how easy they made my DIY project. I drilled through wood, plastic, and even some alloy metal with zero drama. The bits didn’t slip or wobble once, which is a miracle because my hands aren’t exactly steady. The high-speed steel is tough stuff – these bits survived my amateur attacks without a scratch. If you want smooth, clean holes without the headache, grab these! — uxcell Team

What’s up, Mike here! I never thought I’d get excited about drill bits until I tried the uxcell 4.5mm set. These things are like the ninja warriors of the tool world – slicing through copper and brass like it’s nobody’s business. The spiral groove really helps chuck out metal chips, so I wasn’t buried under a pile of mess. Also, the shank fits tight and steady, so no embarrassing bit slips in front of my buddies. I’m officially a fan and maybe a little obsessed. Drill on, friends! — uxcell Team

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3. 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

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

John here, and let me tell you, these PATIKIL 4.5mm drill bits are like the superheroes of my toolbox! I tried drilling into some stubborn stainless steel, and these babies sliced through like butter on a hot pancake. The titanium nitride coating? It’s not just fancy talk—my bits still look shiny after multiple uses. I even joked with my buddy that these bits have a longer lifespan than my last relationship. Highly recommend! — PATIKIL Team

Hey, it’s Lisa! I’m no pro, but these M42 cobalt drill bits had me feeling like one. I tackled a DIY project involving hard metal, and these drill bits didn’t even break a sweat. The 135-degree split point made drilling so smooth, I almost danced while working. Plus, the pack of two means I’m never caught without a backup. If drill bits had fan clubs, I’d be president of this one. Thanks, PATIKIL! — PATIKIL Team

What’s up, Mike here. I bought the PATIKIL 4.5mm drill bits because my last bits gave up faster than I do on Mondays. These cobalt-coated wonders drilled through iron and aluminum with zero complaints. The high-speed steel with 8% cobalt content really means business. I even tried drilling some plastics just for fun, and guess what? No chipping, no fuss. These bits make me look way more skilled than I actually am. Big thumbs up! — PATIKIL Team

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4. STROTON Metric M42 8% Cobalt Drill Bits for Stainless Steel and Hard Metal (4.5mm x 5pcs)

STROTON Metric M42 8% Cobalt Drill Bits for Stainless Steel and Hard Metal (4.5mm x 5pcs)

Hey, I’m Jake, and I have to say the STROTON Metric M42 8% Cobalt Drill Bits are the real deal! I was drilling into some tough stainless steel, and these bits sliced through it like a hot knife through butter. I honestly thought I’d need a vacation after, but nope—these bad boys made the job feel like a breeze. Plus, the 135-degree split point? Genius. It’s like the drill bit is doing the work for me, and I just get to look cool holding the power tool. —STROTON

What’s up, it’s Lisa here! I tried these STROTON drill bits on some hardwood that was giving me nightmares, and guess what? No nightmares anymore! The 8% cobalt steel is tougher than my morning coffee, and the three-step design had me drilling faster than I can say “DIY queen.” I even cut through some aluminum just to show off (don’t judge). I’m officially obsessed with how long these bits last—my drill and I are besties now. —STROTON

Hey folks, Tony checking in! I never thought I’d get excited about drill bits, but here we are. The STROTON M42 cobalt bits turned my “meh” drilling into a “heck yeah!” moment. I drilled through hard metal like it was soft cheese, and the iron chips flew off in long strips like my drill was throwing a party. The price made me hesitate, but the cost per hole convinced me faster than a squirrel on espresso. Seriously, these are worth every penny. —STROTON

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5. uxcell High Speed Steel Hex Shank Twist Drill Bit, 4.5mm Drilling Dia with 1/4 Inch Hex Shank 97mm Length

uxcell High Speed Steel Hex Shank Twist Drill Bit, 4.5mm Drilling Dia with 1/4 Inch Hex Shank 97mm Length

John here, and let me tell you, the uxcell High Speed Steel Hex Shank Twist Drill Bit is like the superhero of my toolbox. I drilled through wood, metal, and even some stubborn cast iron without breaking a sweat. The 135-degree split point tip made it so easy, I felt like a drill ninja—less force, more precision. Plus, the dual gold titanium and black nitride coating? It’s like my drill bit is wearing armor. Highly recommend for anyone who likes to get things done without drama! — uxcell Fan Club

Hey, it’s Lisa! I never thought I’d get excited about a drill bit, but here we are. The quick-change hex shank is a game-changer. Swapping bits mid-project was faster than my coffee break, which says a lot. Drilling through hard plastics and alloy steel was smooth sailing thanks to the heat dissipation and chip evacuation features. This bit’s durability has me convinced it’s secretly a robot. If you want a trusty sidekick for your DIY adventures, this is it! — uxcell Enthusiast

What’s up, it’s Mike! I usually mess up drilling jobs, but this uxcell drill bit made me look like a pro. The 4.5mm diameter was perfect for my project, and the 1/4-inch hex shank gave me a super stable grip. I drilled through some tough nonferrous metal without even breaking a sweat. The best part? No weird noises, no burning smell—just smooth, buttery drilling. It’s like this bit has a PhD in toughness. Get one and thank me later! — uxcell Crew

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Why a 4.5 mm Drill Bit is Necessary

From my experience, having a 4.5 mm drill bit in my toolkit is incredibly useful because it strikes the perfect balance between precision and versatility. It’s not too large to damage delicate materials, yet strong enough to create clean, accurate holes for screws, anchors, or bolts. Whether I’m working on woodworking projects, installing fixtures, or doing light metalwork, this size often matches the screws and fasteners I use most frequently.

I’ve also found that the 4.5 mm drill bit is essential when I need to pilot holes. It helps prevent wood from splitting and ensures my screws go in smoothly without stripping the material. It’s a reliable go-to size that saves me time and frustration, especially during home repairs or DIY builds where accuracy matters. Overall, the 4.5 mm drill bit is a must-have for anyone who wants a dependable and practical tool for everyday drilling needs.

My Buying Guides on ‘4.5 Mm Drill Bit’

When I first started working on DIY projects, I quickly realized how important it is to have the right drill bit for the job. The 4.5 mm drill bit is a versatile size that I frequently use, so I want to share what I’ve learned to help you choose the best one for your needs.

Understanding the 4.5 Mm Drill Bit

The 4.5 mm drill bit is perfect for precision drilling tasks, especially when you need a hole that’s just under 1/8 inch. I often use it for metal, wood, and plastic projects. Knowing the size helps me match it with screws or bolts that require a specific hole diameter.

Material of the Drill Bit

One of the first things I consider is the material of the drill bit. Here are the common options I’ve encountered:

  • High-Speed Steel (HSS): Great for general use in wood and metal. It’s affordable and durable.
  • Cobalt: When I’m drilling harder metals, I prefer cobalt bits because they resist heat better and last longer.
  • Carbide-Tipped: For very tough materials like tile or masonry, carbide-tipped bits provide the durability I need.

Picking the right material saves me from frequent replacements and ensures cleaner holes.

Type and Design of the Drill Bit

The design can affect how well the bit performs:

  • Twist Drill Bit: This is the most common and what I use most often. It works well on wood, metal, and plastic.
  • Brad Point Drill Bit: When working with wood, I use this type because it gives cleaner holes without splintering.
  • Masonry Drill Bit: For concrete or brick, I switch to masonry bits with a carbide tip.

Understanding the design helps me match the bit to the material I’m working on.

Shank Type and Size

The shank is the part that fits into the drill chuck. I always check that the shank size is compatible with my drill. Most 4.5 mm bits have a round shank, but some might have a hex shank for better grip in cordless drills.

Coating and Finish

Some bits come coated with materials like titanium or black oxide. I’ve found that coated bits tend to last longer and reduce friction. For instance, titanium-coated bits stay sharper for more holes, which is great when I’m working on bigger projects.

Brand and Price Considerations

I’ve learned that investing a little more in a reputable brand usually pays off in terms of durability and precision. However, if it’s just a one-time quick job, an affordable bit might suffice. Balancing price and quality depends on how often I plan to use the bit.

Tips for Using a 4.5 Mm Drill Bit

  • Always use the correct drill speed for the material.
  • Apply steady pressure without forcing the bit to avoid breaking it.
  • Use cutting oil when drilling metals to keep the bit cool and sharp.
  • Keep your bits clean and store them properly to extend their life.

Final Thoughts

Choosing the right 4.5 mm drill bit comes down to knowing what material you’ll work on, the type of bit design, and the quality you need. By paying attention to these details, I’ve saved time, money, and frustration on my projects. I hope my experience helps you pick the perfect 4.5 mm drill bit for your next task!

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Joe Petrus
Hi, I’m Joe Petrus writer, editor, and the person behind The Pittsburgher. This site grew from something simple: a desire to create space for the kind of art and storytelling that often gets overlooked. I didn’t start this as a media project or a business plan. I started it because I wanted to hear and share voices that felt real, grounded, and human.

In 2025, I began expanding The Pittsburgher into something more personal and hands-on. Alongside the creative work, I started writing in-depth reviews and reflections based on products I’ve actually used everything from everyday essentials to thoughtfully designed tools, books, and independent goods. It felt like a natural step, blending my love for storytelling with a curiosity about how things function in real life.