Best Drill Bits for Stainless Steel

Drilling tough surfaces is never easy. It’s even harder if you choose a bad drill bit because not every drill bit will pierce through tough surfaces like stainless steel, iron and hardened steel bolts.

The only secret lies in choosing a drill bit that’s squarely designed for boring and hard surfaces. The best drill bits for stainless steel will make your drilling work on hard surfaces as easy as ABC.

These drill bits are strong and do not lose their sharpness even after working for long on hardened surfaces. Here, we’ll take a look at the best drill bits for hardened steel to make your metal drilling work a lot easier.

Best Drill Bits for Stainless Steel (2020 Reviews)

1. COMOWARE Cobalt Drill Bit Set

The COMOWARE Cobalt Drill Bit Set are the top flawless drill bits for stainless steel you’ll ever find. The set is comprised of all drill bits sizes to fit your every usage.

The drill bits are made with a twist design and a 135-degree split point for precise performance. That means you can work on several holes with minimal walking and at a faster rate.

They’re not only appropriate at drilling holes, but also extending the diameter of the existing holes. They’re sharp and do not manifest signs of wearing.

The best thing is that the first drill bit will look like new even after application, and that means the whole package will last you a while. They also work well on several surfaces like hardened steel, plastic, cast iron, wood and aluminum.

If you’re looking for an affordable drill bit for stainless steel then this one is probably the best choice. But that doesn’t mean it is flimsy, the bits are sturdy and work so well as described without overheating; even better than the allegedly expensive brands.


  • Sturdy drill bits
  • Several sizes to suit different applications
  • Price is great


  • We wish the package contained drill bits of up to ½-inch size

2. Bosch CO14B Cobalt M42 Drill Bit Set

The Bosch CO14B is made with durability in mind and do not overheat whether they’re applied on cast iron, stainless steel, aluminum and light-gauge metal.

Because the drill bits are quality-built, you’ll be able to drill on tough applications without frustrations. They have 10-times longer life when compared to standard drill bits.

All the 14-drill bits are versatile to suit all your drilling applications. They’re sharp and delivers a smooth drill without wearing out. You’ll love their high-performance accompanied by fast delivery with little effort.

The drill bits are spiral-shaped to help discharge the wastes fast. Plus, they’re made with a split point to prevent walking and skating for a smooth delivery.

For beginners, the drill bits are easy to use. You’ll also be pleased by the nice case that works well to easily access and select the drill bit of your choice.


  • 14-versatile drill bits
  • Heavy-duty
  • High-heat resistant


  • Slightly expensive

3. CO-Z M2 Step Bit

The CO-Z M2 Step Bit is a versatile single drill bit that drills up to 18 different holes of different diameters. It’s a great drill bit if you want to save on effort and time spent to change from one drill bit to the other.

The product is made with a 3-sided shank design to prevent the split bit from wandering away the hole. As the bit rotates, the shank keeps the bit inside so it doesn’t slip out or spin within the chunk.

The tip is sharp and strong. It can drill on PVC, wood, aluminum as well as tough products like steel and metal sheets. Plus, it doesn’t overheat on tough surfaces and so, drill holes will always be smooth.

The openings are made with an X-design for efficient discharging of wastes. When drilling, these openings facilitate an accurate-sleek drilling and prevents the wastes from scattering.

You’ll love its high-speed performance as it can drill more than 100-holes when compared to convectional step bits that drill just 20-holes on iron sheets.


  • 3-sided shank design keeps the drill bit in place
  • High-speed performance
  • Great quality


  • Wish the package had two or more drill bits

4. Stroton Metric M42 Cobalt Twist Drill Bits

Like popular drill bits, the Stroton Metric M42 can drill through softer surfaces like plastic and aluminum as well as hard materials such as hardwood, hard metal and stainless steel.

The package comprises of 19-drill bits pieces of different length and diameter to suit all your jobs. The material is strong, comprising of cobalt steel for long life.

It holds up well and does not slip up. When compared to other generic step drill bits, this one operates at high-speed and does not wear out since it’s made to resist heat even on tough materials.

The tip is made with a 3-step design to drill with little effort. The 135-degree design allows the tip to drill in such a way that it does not move around (walking) the working spot. This leads to a smooth hole.

Although, these drill bits are a bit pricey, they work extremely well so they’re worth the price. Plus, they’re not only appropriate for fresh drills but also to expand or improve on existing holes.


  • 19-drill bits pieces of different length and diameter
  • 3-step design to minimize walking
  • Drills fast


  • High price

5. Drill America High Speed Steel Drill

Drill America has been the lead brand in the production of drill bits for quite a long time. The Drill America High Speed Steel Drill Bit Set is made with a 135-degree sharp drill point that penetrates the toughest materials such as titanium, Inconel and stainless steel.

The product is made with gold oxide finish that act as lubricant to prevent its surface from wear when you’re working on tough and hard surfaces.

Unlike the generic speedy steel drill bits, these ones have a longer operating life. Plus, they hold up nicely, running straight, leading to incredibly decent bits.

The set contains 29-pieces of varying lengths permitting you to drill holes of varying lengths and widths. Its longest drill bit has a length of 6-inches.

Yes, they are pricey, but they have a long life since they can be sharpened after prolonged use. They sharpen amazingly to look like new.

The drill bits are packaged spirally in a canister, so it’s easy to carry, access the pieces, then place back in the labelled slot once you’re done. The packing case is tight and waterproof.


  • Extremely sharp
  • Can be re-sharpened
  • Great carrying case


  • Pricey

How to Choose the Best Drill Bit for Hardened Stainless Steel and Metal


When looking for drill bits for metal and stainless steel bolt consider if it is versatile to drill on all materials. A great drill bit should drill on wood, plastic, aluminum and iron. Ideally, it should be able to perform well on soft surfaces as well as tough surfaces.

Shank shape/design

The shank design allows the drill bit to operate at a high speed without slipping from the chunk. If the shank is round then it would come off at high speeds. The shank design connects tightly on the drilling machine making the drill bit firm when you’re drilling.

Drill Bit Split Tip Angle

A 135-degree drill bit is the most suitable for drilling holes on tough surfaces like stainless steel. The design allows the tip to drill straight without “walking” around the working spot.

Drill Bits Material

There are several materials that make up the drill bits, so it’s important you place your focus on the material rather than the glittering beautiful appearance. For tough surfaces, it tougher because a flimsy material will be useless from the word go.

Cobalt steel, high-speed steel and tungsten carbide are top construction materials you should consider for stainless steel and hardened steel bolts. These materials are hard and can work on several projects for long periods. They are sharp and do not wear out or lose their sharpness since they have the ability to resist heat even at high speeds.

Avoid high and soft low carbon steel because they don’t hold well when working on tough surfaces at high speeds. Besides, they become blunt after prolonged use and may require constant sharpening after shorter spans of use.

Drill Point Shape

Twist and split bit point shapes are the best for drilling stainless steel and other hard surfaces like iron. The split point is self-centering and that’s what makes it ideal for boring surfaces. The two bits are sharp and give rise to precise and decent drill bits.

Drill Bit Coating

Typically, you’ll find three types of coats on different types of drill bits. We have titanium nitride, black oxide and bronze oxide coating. Any of the these will work exceptionally on tough surfaces.

The coat makes the surface tough and increase the performance of the bits while maximizing on working life. It does this by protecting the top surface from corrosion and wear when the drill is running at high speeds.

Number of Drill Bits in the Package

The best package should contain at least 14 to 21 pieces. The pieces should be different in length and width to suit all your working applications. With several drill bits, you’ll at liberty to pick a drill that suits your needs. They’ll also last longer since you only need to pull a piece from the case as need arises.

We also have drill bits that come as a single piece, but with the ability to drill holes of varying lengths and diameters. A classic example is the CO-Z M2 Step Bit. It can drill up to 18 different holes of varying diameters.

How to Use Drill Bits on Stainless Steel

On a drill machine, we have a chunk- that section comprised of three mechanical arms. Insert the drill bit by the shank, then make the arms tight. Make sure the shank is centrally positioned and firm to avert potential vibrations that arise from loosened or damaged drill bits.

Point the split point perpendicularly to the work spot and start drilling. Place the tip gently to the working surface and allow the machine to move freely. Don’t use a lot of force. Applying too much force will cause the drill bit to jam.

Reduce the speed if the machine starts to produce some squeaking noise. You can also take some brakes and allow the drill bit to rest. Running the drill bits for too long or too fast could get the bits hot.

How to Maintain your Drill Bits

Clean the Bits

Most drill bits are designed to discharge the wastes as you get the work done. A good example is the CO-Z M2 Step Bit. This product is made with X-shape openings to efficiently discharging the wastes when you’re drilling. They facilitate an accurate-sleek drilling and prevents the wastes from scattering.

However, the openings will not always remove all the wastes so its important to wipe the bits after short periods to prevent the debris from clogging within the lines.

Clean the bits again with a clean clothing when you’re done. You can also use a toothbrush to clean up debris that accumulates in the inner sections of the drill bit.

Sharpen the Bit and Oil

Just like a household knife, a metal drill bit will require to be sharpened if you want to increase the performance and operating life.

Oil the bits once you’re done; and the bits are fully cleaned. Oiling prevents rust, preserves the surface and prepare the bits for use at any time. After oiling, store the bits in the case until the next use.

How to Sharpen a Drill Bit

We have simple sharpening tools for small projects and complex sharpening machines suitable if you’re running commercial projects. A metal glider is the most popular for sharpening blunt blades and edges. 

To sharpen a drill bit, position the edge at 59-degrees and start sharpening. Placing the bits at wrong angles will lead to uneven sharpening.

Final Thoughts

There are lots of drill bits out there, so it’s important you’re vigilant if you’re on the lookout for one. Honestly, not every one of those brands will work to your expectations. You’ll need to filter through all the brands which could be exhausting and time wasting.

Fortunately, I did all the work for you. These drill bits I’ve selected will work well not only on stainless steel and tough surfaces, but also on soft and thinner materials like aluminum and plastics. The best drill bits for stainless steel will serve you the longest time to enjoy your drilling work like you’ve always wished.

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