Best Drill Bits for Hardened Steel

Drilling through wood and plastic is easy if you choose a proper drill bit type. But drilling through hardened steel is quite tough. Here, you cannot use any universal or ordinary drill bit.

If you choose the wrong drill bit here, then you may mess up with the whole job.


Here are my recommended products picked out through amazon you would be interested in depending on your budget…

SaleBest Value
Metric M42 8% Cobalt Twist Drill Bits Set for Stainless...
Metric M42 8% Cobalt Twist Drill Bits Set for Stainless...
3 Steps Desigh for Cutting through Stainless Steel,Hard Metals,Aluminum,Plastic.
1/4' M35 Cobalt High Speed Steel HSS Twist Drill Bit for...
1/4" M35 Cobalt High Speed Steel HSS Twist Drill Bit for...
135°Split point, straight shank, sharp spiral groove, coffee bronze coating.; Flute length 2 7/16"(63mm), total length 3 15/16"(101mm).

Are you looking for more cheap Drill bits for hardened steel?

We will drive you through complete technical & pricing comparisons for hardened steel.

Top 5 Hardened Steel Drill Bits Reviews

As a rule of thumb, we normally choose a drill bit of a harder material, but this is not the case here.

Before we dig in deeper, please read to have more clarity on the nomenclature that helps you understand and choose the best one for your job.

A strong heat-treated HSS drill bit is required for this job. High-speed steel is an iron-based alloy that may contain Cobalt, Titanium, Zirconium, Vanadium, etc. Commonly it is cobalt included.

For an easy approach just grab a Cobalt HSS to drill through-hardened steel.

Let us see the top-rated list of Drill bits around.

1. Metric M42 8% Cobalt Twist Drill Bits Set

Cobalt drill bits that are of premium quality, as you can see, 8% cobalt is there. This gives a very polished surface to the drill bit. These Cobalt drills are cable to run 3 to 5 times.

Price is a bit higher for this particular drill bit set due to cobalt percentage, but if we count as ‘Hole’ per buck, we are quite fine.

The split point is 135 degrees mean it is good for hard and tough materials.

Sharp edges of the bit produce long chipping that ultimately will reduce friction & heat.

>>> Check the Latest Irwin Drill Bit Amazon Prices >>>

What We Like!
  • Three-step design starts drilling immediately, no ‘Walking.’
  • Premium Quality 19 pieces enough for any job requirement
  • Can go through Hardened steel smoothly
  • Cobalt alloy increases the life span & durability.
  • A variety of sizes are available
Things to Consider!
  • Costly but produces more ‘Holes’

What’s Our Take…..

A premium look and quality give you extra reliability when drilling through tough surfaces. No chips and no mess like grinding due to powder formation. These bits can work faster 3-5 times than that of the ordinary in the market available.  These bits can also cut through stainless steel, hardwood, and softer materials like plastic & aluminum.

2. COMOWARE Cobalt Drill Bit Set

COMOWARE Cobalt M35 Drill Bits are also of good quality, with 5% of Cobalt included in steel alloy.

It has a gold finish and a round straight shank. These are available at a lower price than the Metric 42%. The reason is the same low Cobalt as Metric bits.

It can cut through hardened steel as well as Cast Iron, high-temperature alloys, titanium alloys, hard plastics, and hardwoods – Aluminum also can be drilled.

>>> Check the Latest Comoware Drill Bit Amazon Prices >>>

What We Like!
  • M35 means 5% of cobalt and hence cheaper
  • 135° split angle to make it faster
  • You can drill several materials.
Things to Consider!
  • Separate lubrication is also required.

What’s Our Take…..

Perhaps these are the cheapest ones available in the market with the best quality. Hardened steel needs extra care while drilling through, but this 135-degree angle helps make a concentration point easily. 15 pieces are available and are enough for any job. Use some lubrication while drilling as these don’t have butter lubrication.

3. Amoolo Cobalt Drill Bit Set

Amoolo Cobalt Drill Bit Set also contains 5% of cobalt – M35 Cobalt High-Speed Steel. The good thing is Amoolo gives you 90 days refund and a 100% cash refund in case if anything went wrong as per their described specifications.

Cobalt drill bits are of high quality and are used by professionals. Cobalt addition makes an iron alloy the increases the strength and toughness of steel and hence the life of a drill bit.

>>> Check the Latest Amoolo Drill Bit Amazon Prices >>>

What We Like!
  • No center punch needed.
  • Steel Industry grade 6542 is used that is harder than 4241 HSS used in other similar drill bits set
  • 13 pieces at a low price
Things to Consider!
  • Could you not use it for High Carbon Steel?
  • Don’t use for glass & porcelain tiles

What’s Our Take…..

Amoolo Cobalt Drill Bit Set is preferred as it is under the supplier’s warranty with a full refund on Amazon order. These drill bits are with guides to use and how to do it. We like it because of the refund policy if you are not satisfied.

4. LETON HSS M35 Cobalt Drill Bit Set

LETON HSS M35 Cobalt Drill Bit Set is best for a casual user and looking for cheaper and the best of your price. This is the same M35 with a 5% cobalt HSS alloy. These can drill through tougher materials as well as with hardened steel.

It can be used in stationary, press drill machines like a radial drill, bench drill, or hand drill chuck.

>>>> Check the Latest LETON HSS Drill Bit Amazon Prices >>>

What We Like!
  • Best for bore machining
  • 135° split angle needs not the center punch
  • Drilling through tough metals made it easy.
  • Cobalt alloyed HSS helps to improve heat resistance.
Things to Consider!
  • Separate lubrication is also required.

What’s Our Take…..

LETON HSS M35 Cobalt Drill Bit Set is designed specifically for bore machining to deal with much more tough materials at high speed. This twist drill with a round shank has sharp spiral grooves. This can also deal with Aluminum, wood, malleable cast iron with ease.

5. DEWALT Titanium Drill Bit Set

DEWALT Titanium Drill Bit Set is our top priority not because of its brand but also for its quality and reliability. This is Titanium Pilot Point gives an extra edge life. These bits give maximum speed and life in stainless steel and other hard metals.

Its tapered web gives greater durability to reduces the breaking of drill bits. Sizes are included from 1/16-inch to 1/2-inch in a hard case.

>>> Check the Latest DeWalt HSS Drill Bit Amazon Prices >>>

What We Like!
  • The nice gold finish of bits
  • 14 Pc with Pilot Point tip longer life than black oxide
  • A pilot point tip eliminates walking.
  • Minimum cost to deal hardened steel
  • Bits are OK with any standard drill
Things to Consider!
  • A bit costly
  • I need to clean tips often.

What’s Our Take…..

Titanium coating is always preferable as it gives extra life at a minimal cost. We can say it is the best available in the lot as you can use these for many purposes. This titanium coating helps to get 3 times more holes than ordinary black oxide drill bits.

Take-Home Point

Try to grab the maximum possible information about your project. This is always advisable to count the number of holes. This will help choose any preferred drill bit set no need to go behind the brands until you have an extra budget and need more quality.

Make sure to estimate your project duration and the budget. If you are high on budget and looking for a longer project/project, always go with brands like Dewalt, Bosch, and Drill America. Another thing always sees if it is made by America, Japan, Germany, etc.

FAQ’s and Answers

What are the best drill bits for hardened steel?

Cobalt bit, which is a type of HSS, is specifically designed for this job.

Is cobalt or titanium drill bits better?

Cobalt has a bit edgy, as it is considered harder than Titanium. With cobalt, you will have a well-polished surface on your drill bit.

How do you drill through hard steel?

Slow speed, proper drill bit, and the drill machine. Do follow the instructions, and here you go. At the start, use Stub the shorter bit and the go for jabber if required a longer hole. Also, maintain the optimal speed during drilling. You can adjust it from the drill machine. Avoid hammer operation also.

Can you soften hardened steel?
Yes, annealing is the process to do it. It is a long and costly process and is done in the industry, like putting the hardened steel piece in a gas-fired furnace as per the annealing cycle of that particular steel type.

Are cobalt drill bits worth it?

If your job is to drill through hardened steel or any tough material, it is OK to go with it. As I said earlier, we are going to buy the ‘Holes,’ not the bit. Cobalt drill bits are the best ones for hardened steel.

Do you need a special drill bit for metal?

Yes, as regular drill bits may ruin themselves and mess up your project.

What is the right design for drill bits meant for hardened steel?

Cobalt & Titanium HSS alloy based drill bits are recommended for hardened steel. These bits are strong and reliable.

How can I sharpen my drill bits?

Yes, but before this, read the buyer’s guide and recommendations well. The sharpening of drill bits has become very popular nowadays. A bench grinder or a costlier diamond file will be helpful.

Does the length of the drill bit matter?

Yes, stub or shorted bits are preferred unless you need a deeper hole. Still, at the start, it is preferred to use the shorter one.

What is the common high-speed steel for bits?
There are 5 levels of HSS drill bit grading;

  • T1 – Tungsten Steels
  • M1 – Molybdenum High-Speed Steels (HSS)
  • M2 – Molybdenum High-Speed Steels (HSS)
  • M7 – Molybdenum High-Speed Steels (HSS)
  • M50 – Molybdenum High-Speed Steels (HSS)
  • M35 – 5% cobalt
  • M42 – 8% cobalt

The best one is with higher cobalt percentage here. You can read more about these are at Wikipedia.

What are the different uses of Hardened Steel?
This is used in car parts, cranes, truck parts, guns, knives, etc.

~Happy Drilling~


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David Houghton
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1 thought on “Best Drill Bits for Hardened Steel”

  1. The great things of your article you talk about the hidden things which is the common high-speed steel for bits. I used DEWALT Titanium Drill Bit Set which is undoubtedly a good choice for newbie and I also recommend COMOWARE Cobalt Drill Bit Set. Amazing thoughts ..

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