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TOP 3 Best Drill Bits for Hardened Steel Bolt – Reviews

If you’re an artist, a carpenter, a glassmaker or a DIY geek who spends most of the time creating handmade goodies and you’re always dealing with steel in your crafts, then you might find this article very useful and handy.

TOP 3 Best Drill Bits for Hardened Steel Bolt – Reviews
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If you’re an artist, a carpenter, a glassmaker or a DIY geek who spends most of the time creating handmade goodies and you’re always dealing with steel in your crafts, then you might find this article very useful and handy.

We’d like to introduce you to drill bits, which will be a great aid for your work. Drill bits are tools designed to create holes in different materials. They have different shapes, sizes, and uses.

Below, you shall find the best drill bits to be used, if you’re a person who loves working with steel, especially the hardened one.

Best Drill Bit for Hardened Steel in April, 2021 – Comparison

Drill America M35 Cobalt Drill Bit – Top Pick

This is one of the most reliable kits when it comes to drilling hardened steel. Being made from Cobalt makes it a nice choice, as mentioned before.

Kit’s Content

The set comes with 29 drill bits with different sizes in a plastic case with labeled compartments to ease the identification and organization of the different pieces.


The bits are made from Cobalt with gold oxide finish. The Cobalt provides durability, protection, and resistance to high temperatures while drilling.

The gold oxide acts as a lubricant and adds extra protection so that the bits don’t wear off.


The 135-degree point allows strong penetration leaving no pilot holes, also the chips produced are tiny, which prevents clogging of the holes.


Its price is too good compared to the quality and the performance.

We do recommend this kit because of the many good reviews, strength, durability, reasonable price and for the many pros they have as follows.


  • Has different sizes suitable for different holes
  • Easily stored and carried, thanks to the good packaging
  • Doesn’t cause a hassle and mess
  • Rust and water-resistant
  • Fits corded and cordless drills
  • Has a marked index for each bit
  • Conforms to ANSI


  • None

Dewalt DW1263 Cobber Drill Bit Set – High Performance

This is another great set that has great performance, creates clean holes and suitable for commercial uses as well.

About the Set and the Package

The package is so neat with a heavy and strong case to protect the 14 bits of different sizes. Moreover, it has labeled slots for each bit to help you stay organized.


Being made from strong industrial Cobalt, allows the bits to go through stiff metals and hardened steel in a fast and sharp way.


Having a Pilot Point end prevents walking to ensure precise performance. It also offers fast and sharp cutting. Using this kit will help you choose a suitable bit for each task, so you won’t need to try different holes.

Overall, this is a great choice whether you’re using it for simple tasks around the house, or for more complex tasks in your workshop.


  • It has a unique, strong and protective case that allows durability
  • Doesn’t require high pressure
  • Different sizes of bits for multiple tasks


  • If you applied too much pressure, small bits may break

Irwin Industrial Tool 63221 – Budget Friendly

Another great tool that is worth mentioning and considered a great option for those looking for great abrasive resistance.


Characterized by its top and super performance with the aid of the 135-degree point that makes penetrating the strongest surfaces easy.

Also, it aids with the chip ejection and that makes the job so smooth.


This is what makes this kit special as it’s made from M-42 Cobalt allowing for high penetration, strength, and resistance.


It comes with 21 pieces of different sizes to allow different tasks.


This is the best option if you’re on a strict budget and you don’t want to spend a huge amount of money and yet get a good kit.

This kit isn’t recommended for heavy and tough work. However, it’s a good option if you need a kit at home for certain simple tasks.


  • Budget-friendly option
  • Has 21 different pieces for various tasks


  • Not suitable for complex tasks

Best Drill Bit Set for Hardened Steel – Buyer’s Guide

Working with hardened steel is different from working with other materials like wood, glass, plastic or even ordinary steel. Hardened steel is one of the toughest materials to work with as it’s highly treated to become that firm. Therefore choosing the right kit is mandatory to keep your work professional and clean.

There are four main factors that you need to be familiar with when choosing the kit.

  • Material
  • Coating
  • Flute’s design
  • Technique


Since we already know that hardened steel is one of the toughest steel forms, for a drill bit, we’re looking for some material that’s stronger than steel.

How so? Let’s explore some options.

  • Soft Low Carbon Bits

They’re the cheapest options on the market, always need sharpening and aren’t so durable.

  • Cobalt

It’s on the top list to be used for hardened steel and it’s good for hand drills as well.

  • Titanium

It’s more suitable for normal steel and it’s cheap.

  • Tungsten Carbide

It drills through hardened steel, however, it requires special attention and is not recommended for beginners or home users.

  • Diamond

It works with hardened steel, however, it wears off so quickly.


Choosing a bit with a strong coating is vital for the durability to provide good protection against corrosion and rust. A good coating is supposed to include black oxide and TICN.

  • Black Oxide: provides heat resistance, low friction, and good corrosion resistance.
  • Titanium Nitride (NIT): made of ceramic, so it increases durability by three times.
  • Bronze Oxide: auxiliary coating and achieve high-speed steel.

Flute’s Design

There are two different designs as follows:

  • The parabolic: This design is more suitable for soft materials as glass and wood.
  • The 30-degree: It is designed to work best for hardened steel.


Choosing the right material, design, and coating is fundamental, however, your drilling technique is way more important because it affects the quality of your work. Here are some tips to ease your work:

  1. Work slowly and patiently
  2. Use oil continuously to make it softer
  3. Apply constant pressure and don’t stop until you reach the bottom because the steel will harden

Taking Care of Your Drill Bit

If you’ve just purchased an expensive kit and you’d like it to perform perfectly through time, you need to take certain steps that are so easy, yet mandatory as:

Clean and Wipe the Bit

While working, make sure you wipe and clean the bit every 10 minutes to ensure high performance. Also, when the work is done, make sure to clean it properly before putting it in the case.

Apply Oil

When your work is done, apply some oil after cleaning.


Store them in a dry and cool place.

Use a Sharpener

Always sharpen your bits after every task to have them ready and strong for the next task.


How to use the drill bit?

There is a part called chunk that has three arms, you should insert the bit into it and tighten the arm around a bit, then you’re ready to go.

How to sharpen the bits?

Get a metal grinder and hold the sharp end of the bit in 59 degrees and the grinder will do the job.

How to remove a broken drill bit?

Use a screw remover in an anticlockwise direction to remove the bit.

How to deal with a vibrating drill bit while working?

Insert the bit correctly in the chuck and tighten it, if it still vibrates, check the bit it might be broken or bent.

How to prevent the bit from getting hot while working?

Use water or oil on the bit while working to decrease its temperature, but be careful if you are using an electric drill.

Did You Get Lost?

We know that choosing the best drill bits isn’t easy, especially when you’re dealing with hardened steel. However, in this article, we covered 3 perfect kits and we’re sure that you shall find what you’re looking for in one of them.

Also, if you don’t feel sure about which one to purchase and you’d like to explore more, we believe that our buyer’s guide section will help you.

So pay attention to the material of the bits and always go for the cobalt ones. Concerning the design, buy the 30-degree type because it’s perfect for the hardened steel.

Remember that even buying the best kits won’t make them last a lifetime, and you have to take care of them by cleaning, drying, applying oil while working and storing them well.

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