5 Best Drill Bit for Cast Iron

Have you ever noticed that 2-4% of cast iron is carbon? Do you really know? What could be the Best Drill Bit for Cast Iron to cut properly for the drilling project since they are versatile metal elements?

The major mistake we make is picking any drill type since the primary function of the drill bit is to drill through various materials. For drilling cast iron, the conventional drill bit set is insufficiently suitable. Therefore, you will need a sturdy, versatile drill bit kit with a few comfortable qualities that promise no fragility while boring into cast iron objects.

DIYers Pick: 5 Best Drill Bit for Cast Iron

Image Product Name Specification   Price
backpac COMOWARE Titanium Brand: COMOWARE
high-speed steel
Color: Gold
Kit components:
13 pieces
Finish Type: Titanium
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backpac Metric M42 Brand: STROTON
Name of the pattern:
19 pieces
Material: Cobalt
Part Number:
M42 Cobalt-8 (19 pcs)
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cordlessblower Amoolo M35 Brand: Amoolo
Material: cobalt steel
Cutting Diameter:
0.25 inches
Shank Type: Round
Cutting Angle String:
135 Degrees
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cordlessblower DEWALT Titanium Brand: DEWALT
Style: 21-piece cast iron drill bit
Color: Yellow Titanium Pilot Point
Country of Origin: China
Item model number: DW1361
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cordlessblower Hymnorq Metric M35 Brand: HYMNORQ
Style: 13 pieces in a plastic case
Material: cobalt steel
Finish Type:
Bronze Oxide
Shank Type: Round
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You should consider factors like strength, cutting accuracy, convenience, heat resistance, endurance, as well as storage facilities. We have enrolled five top-class drill machine bits for cutting iron materials that will offer you every feature that you expect from your tool. So, let’s dive into the review section.

Top Drill Bit

COMOWARE Titanium 13-Piece Cobalt Drill Bit Set

  • High-speed steel, or HSS, with 5% cobalt is used in the COMOWARE strong drill bit set to enhance durability, increase heat resistance, and increase abrasion resistance.
  • For hard substances, M35 cobalt HSS is more appropriate.
  • It features the ideal 135-degree split point with a twist design to clear chips, prevent walking, and remove dust quickly.
  • Premium quality from Cut-throat, with a drilling capability of more than 200 holes in 1/16-inch stainless steel.
  • Particularly effective at cutting through hard metals like cast iron, stainless steel, titanium alloy, high-temperature alloy, plastics, wood, or other soft elements.
  • For convenient storage and management, the set includes a drill bit holder with a size index.
  • The 13 pieces available are: 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 15/64, and 1/4 inch.
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  • Brand: COMOWARE
  • Material: high-speed steel
  • Color: Gold
  • Kit components: 13 pieces
  • Finish Type: Titanium
  • Shank Type: Straight
  • Cutting Angle String: 135 Degrees
  • Package Dimensions: 5.91 x 3.58 x 0.75 inches
  • Customer Rating: 4.5

As drill bit users, professionals constantly demand a tool with versatile performance and broad compatibility. Have you ever observed that the best things on the market are often offered by well-known brands? So, here is the masterclass titanium, HSS, and cobalt drill bit kit with 13 distinct parts produced by the Comoware brand. It’s a set of cast iron drill bits that will make you feel like you got exactly what you wanted.

The drill bit’s accuracy and ease of use indicate that it can cut like a hot knife through butter. What do you really expect? Heat resistance? Accuracy? Controllability? Speed? Easy use? By using this top-quality cast iron drill bit, everything is ensured!

Additionally, you can make more than hundreds of holes in hard surfaces since they have M35 cobalt HSS.  All of the cutting-edge technologies, such as cutting speed, reduce walking and clear particles and chips more quickly. Nowadays, we look for the 135-degree split point, which is also included in this tool. For improved organization, the drill-bit holder and size index are the best features to appreciate.

  • The set of highly effective cobalt drill machine bits. Checking the bits confirms that they are all sharp, and the precise 135-degree split point stops walking and speeds up drilling. Offer high heat resistance when in use and resistance to abrasion. The tool is so ideal for cutting cast iron with 13 separate pieces.

  • When working with heavy metals, it often loses its sharpness. The casing is inadequate in the eyes of certain users.

Runner Up

Metric M42 8% Cobalt Twist Drill Bits Set for Stainless Steel and Hard Metal

  • A premium twist drill bit set made of M42, an 8% cobalt steel (68–70 HRC), will provide extra durability by providing resistance to heat, wear, as well as chipping.
  • Flexible three-step design kit with 19 unique parts.
  • With the powerful, sharp blade, you can cut cast iron, stainless steel, aluminum, or plastic, and operate, the tool, it will be 3-5 times quicker.
  • Instead of grinding through the material gradually with a dull drill bit, the sufficiently sharp bit edge can cut the metal material into long strips of iron chips.
  • More holes will be made than with any other standard drill bit set since the cast iron drill bit has a 135-degree split point and speed control.
  • This is an ideal drilling tool that you can operate for a long time, like an hour, without hassle for your professional or DIY projects.
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  • Brand: STROTON
  • Name of the pattern: 19 pieces
  • Material: Cobalt
  • Part Number: M42 Cobalt-8 (19 pcs)
  • Finish Type: Oxide Coated, Steel
  • Shank Type: Straight
  • Flute Type: Spiral
  • Cutting Angle String: 135 Degrees
  • Package Dimensions: 7.32 x 6.14 x 1.73 inches
  • Customer rating: 4.5 stars

Do you know? According to research, cobalt-containing HSS has better heat resistance, red toughness, wear resistance, and temperature treatment response than cobalt-free HSS. STROTON is a brand that is offering a strong drill bit kit with premium Metric M42 8% Cobalt. This is a reliable tool with excellent sharpness and accurate size. However, the adaptability of the 3-step technique, the split point of 135 °, and the 19 available bits will demonstrate how they perform efficiently and precisely.

Sharp blades work more quickly than conventional ones, so you won’t have to worry about damage! Any cutting project involving hard materials such as cast iron can be completed successfully. Therefore, if you are considering what type of drill bit to use for cast iron, this is the one that will make your experience satisfying.

  • The three-step design of the Metric M42 8% Cobalt Twist power drill makes it simple to drill through tough materials. The bits are really sharp and accurate in size. Can cut through any material for at least an hour without causing damage. It lets you quickly drill a large number of holes and doesn’t overheat rapidly. The best thing about the Stroton brand is its outstanding warranty and customer support.

  • Some users discover it to be fragile after cutting hard metals. But the occurrence is rare.

Best Budget

Amoolo M35 HSS Metal, 1/4″ Cobalt Drill Bit Set for Cast Iron, Hard Metal, and Stainless Steel (10 Pcs)

  • Strong metal bit set, 10 pieces, 1/4″ (diameter, 6.35mm), x 2-3/4″ (length of flute, 69.85mm).
  • Compared to HSS used in other sets of drill bits of a similar size, the industry-grade M35 high-speed steel drill bit set is stronger.
  • This drill bit’s 5% cobalt content boosts wear durability and resistance.
  • For faster metal drilling, a 135° split point is included.
  • Due to its extensive grinding process, you will experience reduced frictional heat and accurate drilling.
  • Ideal for cutting through hard metals like cast iron, stainless steel, and sheet metal, as well as plastic, wood, aluminum alloy, and other soft materials.
  • This drill bit comes with a transportable plastic box for storage purposes and management and accommodates the majority of power drills on the market.
  • Offers a 90-day warranty, so please get in touch if you need a replacement or a 100% refund.
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  • Brand: Amoolo
  • Material: cobalt steel
  • Cutting Diameter: 0.25 inches
  • Shank Type: Round
  • Cutting Angle String: 135 Degrees
  • Size: 1/4″ with 10 pieces
  • Package Dimensions: 4.8 x 3.27 x 0.47 inches
  • Warranty: 90 days
  • Customer rating: 4.5 stars

This time, we’d like to introduce another set of Amoolo brand multi-purpose power tool bits. This is a 1/4″ Cobalt Steel 10-piece kit that is compatible with the majority of power drills on the market today. The movable plastic box is amazing for easy organization and storage. Then, high-speed steel of industry-standard M35 with 5% cobalt is used because it boosts sturdiness and wears resistance.

What makes it even more appealing is the fully ground spiral groove style, which reduces friction and erases debris, together with the 135-degree split point and straight shank, which stop walking and enable precise and swift drilling. Cast iron, wood, aluminum alloy, plastic, and other soft materials can all be treated with this tool flawlessly. Their 90-day warranty for a 100% replacement or refund is one additional huge benefit.

  • An excellent M35 cobalt drill set that has good points and works well on wood and thin metals to provide heat resistance and endurance. You’ll have complete control, more cooling efficiency, and improved results. The 69.85-mm flute diameter simplifies how to install a power drill. It comes with a fair price considering its performance, and the 90-day warranty is what you’ll appreciate the most.

  • After a long operation, the set may have the possibility to overheat or become dull. In order to lower the temperature while working, you must add water. Carbon steel and ceramic materials are not compatible with the bits.

Premium Pick

DEWALT Titanium Coated Drill Bit Kit, 21 Pcs, Pilot Point, (DW1361)

  • Strong Dewalt titanium drill bit with a sharp tip and holes free of burrs.
  • The titanium nitride-coated set has a clear lid that lets you readily see the contents at a glance and a clip latch for safe sealing.
  • The drill bit set’s innovative bit-bar construction makes it simple to extract bits and adjust the position.
  • Improved durability from a tapered web helps to lessen breakage.
  • The availability of a clip latch makes safe closing easier.
  • It comes with 21-bit pieces and a convenient carrying and storing box.
  • Drill Bit Sets can organize stray bits and come in various sizes from 1/16″ to 1/2″, and they are housed in a strong plastic container.
Check Price on Amazon
  • Brand: DEWALT
  • Style: 21-piece cast iron drill bit
  • Color: Yellow Titanium Pilot Point
  • Country of Origin: China
  • Item model number: DW1361
  • Material: Titanium Nitride Coated
  • Finish Type: Titanium Nitride
  • Shank Type: Straight
  • Item Dimensions: 8.75 x 8.75 x 1.38 inches
  • Flute Type: Spiral
  • Surface Recommendation: Metal, Wood, and Plastic
  • Warranty: A 30-Day Money-Back Guarantee
  • Customer rating: 4.8 stars

Here comes the popular, Dewalt brand special product that comes with 21Pcs titanium nitride drill bits.  Every driller will appreciate the incredible attributes that the Dewalt DW1361 model offers. Such as the bit-bar type for withdrawing bits and appropriately adjusting them, the tapered web for durability, and the clip latch for a tight closure.

Cannot avoid sharing about the storage and transporting box to carry and organize them from 1/16” and 1/2″. The performance of this yellow beauty from China has already received a 4.8 rating. Don’t underestimate this tool because it offers excellent value for the money while also being sturdy, long-lasting, and durable. Additionally, they are offering a 30-day money-back guarantee. Grab it or it will become market out anytime for huge sales.

  • Absolutely fantastic features and an even more amazing casing. the multipurpose tool with 21 different bits that guarantee accurate hole drilling and bit-bar placement. This drill bit has multiple uses, ranging from metals to plastic and wood. Guarantees a 30-day money-back time.

  • This drill bit set is imperial rather than metric. Not being able to adequately resist heat and sustain pressure. Also, a 1/4-inch bit isn’t strong enough to withstand significant pressure.

Best Overall

Hymnorq Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bits

  • 13 pieces are included in the kit, which can cut through metals like cast iron and stainless steel.
  • Molybdenum and cobalt are added to steel alloy M35, which has 5% cobalt, to produce a hardened alloy with a Rockwell hardness of up to 67 and superior heat resistance.
  • The 135° Quick-Cut points are self-centering and cut faster with less force.
  • When compared to a typical HSS power drill, they can have a life duration of up to 12 times longer.
  • Suitable for common drill chucks and round collet chucks.
  • When it doesn’t cut, you can change the RPM.
  • They have included a downloadable user guide to have better tips to utilize this best drill bit for cast iron.
Check Price on Amazon
  • Brand: HYMNORQ
  • Style: 13 pieces in a plastic case
  • Material: cobalt steel
  • Finish Type: Bronze Oxide
  • Shank Type: Round
  • Cutting Angle String: 135 Degrees
  • Item Dimensions: 5.12 x 0.59 x 2.76 inches
  • Flute Type: Twist Flute
  • Surface Recommendation: Metal
  • Item model number: DC023
  • Warranty: After purchase, the seller offers a 90-day warranty

Metalworking needs a specific type of cobalt steel drill machine. All of the items are the best drill bits for cast iron, so we want to reveal the HYMNORQ 13-piece twist drill bit set with a straight shank, which can cut through any hard materials like cast iron or stainless steel, thanks to its 5% cobalt steel content. It’s an exceptional one for sure! Do you know why? They have a 135-degree cut point, a hardness of 67 or higher, and a twelve-times longer life expectancy than regular HSS drill bits.

The tool’s heavy-duty engineering and stable holding with precise alignment enable the drill bits to quickly and effortlessly cut hard metals. An additional benefit is the ability to change the RPM. Since it’s an excellent drill set with metric bits, if you have misconceptions about how Chinese products aren’t always good, just stay away from the facts. One more exception is that they have a user manual that you can download from the internet.

  • The exceptional M35 cobalt steel, 135° Quick-Cut points, and user manual can be downloaded. Additionally, they have improved grip, heat resistance, and exceptional performance, along with customizable RPM. Such a precise set of drill bits for cast iron is also capable of cutting soft materials.

The smallest amount of pressure could potentially cause the 1/4″ bit to break. Although the product is fine, the casing requires improvement and is not durable enough for any demanding task.

How to Drill into Cast Iron

So, we have suggested our best-picked well researched cast iron drill bit sets. If you ever wonder why these bits exist, the guidelines part will explain why you should grab these tools for cutting cast iron metal. However, having the drill is not an accomplishment. You need the drilling process for accuracy. So, let’s take a look at the step-by-step job of cutting cast iron objects.

How to Drill into Cast Iron

Mark the Spot

Mark a location on your cast iron where you intend to drill first. Highlighting your area will considerably boost your efficiency. However, use a center punch and a hammer, then proceed with the marking.

Get The Ideal Drill Bits

Considering cast iron is brittle by nature, the ideal drill bit should be employed first. What sort of drill bit should I use for cast iron, then? Take a 135-degree, point-angled cobalt bit in your hand.

Then, you must determine the size of the hole you will drill. Keep in mind that a little shorter will perform better when drilling a hole where a screw will stay.

Apply Lubricants

In order to prevent overheating, lubrication should first be applied to your drill bits before use. Cutting fluids are much preferable since they keep your bits safe and stop metal shavings from flying.

Secure Cast Iron With Brace

When the cast iron is not attached to the fixed item, you might need to brace it. Consider using a table vice to hold the object securely on both sides.

Start Drilling Gradually

It’s time to begin drilling on the spot. Start pounding while holding your drill bit in an upright position. Take your time and work in small bits to get the job done.

Clean The Debris

Drag the drill back and forth to clear out any residual debris after the drilling operation. Otherwise, it might create issues while you are taking the next step.

Surface Cleaning With a Dry Cloth

A dry cloth is employed to clean the surface at the end of the process, and a wet cloth followed by a dry cloth is used to do the same task after the first section. Make sure there are no metal particles inside. Now, you can complete your project with an accurate cast iron hole.

Factors to pick the Best Drill Bit for Cast Iron

When purchasing a tool for any purpose, the most important factor is to read the proper instructions. We have included some features that a good drill bit set should have. Hopefully, everything we needed was already in the products we reviewed today. Let’s talk about the features that say you have the right cast iron drill.

Material Type

Carbide, cobalt, or high-speed steel are all possible materials for drill bits. The material type does matter when it comes to cutting cast iron. Cast iron can be cut through with the strongest material, hardened steel.

However, high-speed steel (HSS) or cobalt can provide the most precise and clean metal cut; thus, these two types are commonly used to make effective drill bits for cast iron. However, the ideal option would be black oxide or cobalt steel drill bits.

Bit Size

To achieve an accurate cut and good durability, short bits should be used. They are basically stronger and less likely to break because of their length. Long drill bits frequently twist and break because they are thin and fragile, while short bits are.

Bit Design

Drill bits come in a variety of styles, including split-point, tapered, fish, and v-point designs. In most cases, a properly attached split-point style will guarantee flawless cast iron cutting.

Shank Style

Drill bit ends that fit into the drill and is kept in place by the chuck are designated shanks. The shank or edge that the drill’s chuck accepts as non-drilling material. As a result, for the bit to engage, the chuck and shank sizes should be identical.

In addition to the two types of shank designs—hex shank and no-spin shank, we frequently use three shank sizes:  ½, ⅜, and ¼ inch. Therefore, grab the item that is best for your needs and provides the necessary stability and safety.

Drill Bit Coating

A good drill bit will typically have a titanium or black oxide coating to prevent overheating, reduce resistance, and indeed boost speed.  Make sure you have this feature while buying drill bits for cast iron.

Some Additional Tips Drill Out Cast Iron With Drill Bit

Tips Drill Out Cast Iron With Drill Bit
  • Before proceeding, indent the surface.
  • Use a leveler or a ruler to measure the material’s width.
  • First, keep the speed low and then gradually raise it.
  • If you use your drill bits regularly to avoid overheating, lubricate them.
  • Every time you use step bits to generate large holes, the speed setting should be taken into consideration.
  • Rather than using clothes to clean up extra oil or metal dust, use a rug.

FAQ on Best Drill Bit for Cast Iron

Can cast iron be drilled and tapped?

Yes, it takes effort to tap a cast-iron hole to avoid damaging taps when you come across a hard region. The perfect technique for holding fixtures and jigs is threaded holes in cast iron machine tables. But keep in mind that a casting that has been chill-cooled becomes hard like glass and almost non-machinable.

Is cobalt or titanium drill bits better?

Compared to titanium drill bits, cobalt drill bits are more pricey, but offer heat resistance and good endurance. Drill bits made of cobalt are better suited for tougher materials like cast iron. However, titanium drill bits work well with softer materials.

Will a Sawzall cut cast iron pipe?

Yes, a Sawzall can accurately cut cast iron pipe. Reciprocating saws are preferred by many skilled handymen, contractors, and homeowners because they can be used to cut cast iron with the right-sized blades.

What’s the best way to cut cast iron?

A snap cutter is ideal for working with cast iron objects. However, a saw or cutting tool with a diamond saw blade or a reciprocating saw blade with a carbide tip, is the best option when cutting through tough cast iron in a straight line. Additionally, angle grinders are also effective.


Knock, knock! It’s conclusion time! This article has discussed the best drill bit for cast iron and the most notable features that have made them stand out products on the market. Whether you require power, accuracy, durability, or longevity, or features such as HSS with cobalt, the proper bit size, design, shank type, and coating, our 5 recommended drill bits have it all.

Also, we have the proper guidelines for you as well as the drilling process for cast iron. So, consider all the facts while you buy your tool for your project.

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Samuel H. Murphy is DIY expert and Interior Designer. He is also a part time content writer of Capische. He lives in Warren city, Michigan. He test tools like drill, saw, sander, air compressor etc and helps readers to find out the best tools.

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