6 Best Drill Bits for Cast Iron

Drill bit is the sweet spot of cast iron and our purpose is to dig inside it. When the drill will create a force using an inner mechanism, it releases the power against the cast iron metal. The invincible sturdy nature of it makes every drilling task viable that we had never experienced before. The best drill bits for cast iron comes with the amazing features but we are confused to see its flexibility.

However, it is not fragile at all. Turns out, the tool became lightweight and able to prevent overheating while generating frictions. Many of us look for drill bits that come for the masonry work. We will strongly forbid you to take this into consideration. Because the cast iron will be completely damaged with its wide flutes.

This kind of drill bits are suitable for hammer drilling. While buying a drill bit we consider the sharpness, for example nitrite drill bits are excellent in sharpness, making your drilling accurate, smooth and fast. Today we will tell you everything you should come to know

Handyman’s Pick: Top 3 Best Drill Bit for Cast Iron

Image Product Name Specification   Price
backpac COMOWARE Drill Bit Color: Gold
Material: M35
Finish Type:
Shank Type:
Cutting Angle String:
135 Degrees
Check Price
backpac Metric M42 8% Cobalt Color: Gold
Material: Cobalt
Shank Type:
Cutting Angle String:
135 Degrees
Tool Flute Type:
Check Price
cordlessblower Amoolo 1/4″ Drill Bit Color: Silver/Gold
Material: Cobalt Steel
Shank Type:
Cutting Angle String:
135 Degrees
Tool Flute Type:
Check Price

Do you want to drill a hole like a child lick his finger? With our recommendation of drill bits for cast iron, you will find the top 6 choices. Among them, you can choose according to your required job sites. One of them would be affordable with limited features, another would be excellent but won’t save your bucks that much. So choose wisely after reading between the lines

Our Top Pick

COMOWARE Cobalt Drill Bit for Cast Iron

  • The drill bit has an amazing bit holder for easy carrying and storage.
  • Having a 135-degree split point allows the user to prevent walking and chipping.
  • You can drill on wood, plastic, and metal, all without changing the speed settings.
  • Heat or abrasion hardly damages the bit due to its high heat resistance and durability.
  • Turns out, you can drill on hard titanium alloy without doing damaging the bit edges.

The Comoware Cobalt Drill bits are industry-leading heat-resistant drill bits, which gives you full control to drill into cast iron. Having an abrasion resistance feature, the bits will last for days without you even noticing it. Turns out, a precise 135-degree split point prevents walking and drills faster. You will have no trouble with edge chippings due to its fine twisted design.

The best part is, you can store and organize the bits as there is a bit holder out of the box. With a drilling capacity of more than 200 holes through 1/16 stainless steel, the bits are a Cut-throat example of premium quality.

  • Often a drill bit faces difficulty drilling through materials harder than titanium alloy. However, the Comoware Cobalt Drill bit has an M35 cobalt HSS design that prevents bit chipping on tough materials. Besides, it is highly heat-resistant during work and prevents abrasion from occurring. Turns out, the bit has up to 13 size variations for all DIY or professional projects.

  • Though you can drill on even the hardest of metals, the bit durability is compromised when you drill thick metal sheets. The smaller bits dull easily with slight pressure.

Runner Up

Metric M42 Cast Iron Drill Bit Set

  • The bits have an 8% cobalt steel composite that resists heat and wear.
  • A 3-step design allows fine holes in stainless steel, wood, and even plastic.
  • Having a chip resistance feature, the drill bit can work for hours without damage.
  • You can increase the speed to the maximum without significant damage.

Professional carpenters and construction workers will prefer this drill bit for its hardened material and multi-functional properties. A 19-piece set of bits gives you complete resilience for making holes for all cast iron materials. If you want a long-lasting tool for your DIY or professional drilling projects, this is one of the best drill bit set won’t disappoint you. Besides, the three steps design increases the drilling capacity through stainless steel, Aluminium, plastic, and so on.

Having an M42 8% cobalt steel, the bits are highly heated tolerant and chip resistant. Surprisingly, you can increase the drilling speed up to five times faster than regular drill bits. Though the price is a little high, you will still have a longer service life and a lower cost per hole.

  • Sometimes cast iron can be bulky and thick, making it harder to drill holes. This is why the drill bits have a three-layer design, which passes through any stainless steel and hard metal like butter. Unlike other drill bits, you will have better access to materials other than metal sheets.

  • The only setback of the bit is its price. But then again, you will save money on making more holes for the price.

Best Overall

Amoolo: 1/4″ Cobalt Drill Bit Set for Cast Iron

  • The bit has a flute length of 69.85 mm for easy attachment in power drills.
  • An industrial-grade 6542 high-speed steel structure gives the bits resilience and better performance.
  • Having a 135-degree split point, the bit can drill straight on metallic surfaces with ease.
  • You will have reduced frictional heat and precise drilling due to its fully ground process.

Amoolo M35 is one of the expensive picks on our list. But who will buy this, it will pay back soon. The M35 Cobalt High-Speed Steel drill bit is faster, smoothie, and bore more holes than many others. Suppose you need to work for hours without delay, overheating, or edge erosion. You will get a bit, which fits all the majority of power tools without any hassle.

To increase the wear resistance and overall durability, manufacturers used 5% Cobalt in drill bit raw materials. A fully ground spiral groove design clears any metallic dust from the center for fine hole making.

  • Staying cool during drilling projects is a major concern for most of the mid-budget drill bits. Though the price doesn’t break the bank, you will get full control, longer cooling time, and better performance. A flute length of 69.85 mm allows users to better cope with power tools such as drill machines.

  • You have to add water to reduce the temperature during work. Additionally, working ceramic materials and high carbon steel won’t produce a picture-perfect result.

Premium Pick

DEWALT Titanium Drill Bit for Cast Iron

  • The bits have a pointed tip, which offers burr-free holes on almost any surface.
  • With a fine storage box, you can easily remove and customize the position of the bits.
  • For an increased rigidity over variable surfaces, the bits have patented web taper.
  • You can use it on all metal, wood, and plastic at will.

As the name suggests, the Dewalt Titanium Drill bit has a full set of 21-bit pieces with an easy carrying box. Due to the patented bit-bar design, the drill bit set allows screw removal. Drilling through cast iron and hardwood leaves a perfect hole with minimum edge chipping.

The web taper design enhances the rigidity of the bits and allows easy penetration. Your bits won’t break or bend even after hours of usage. A proprietary pilot point tip delivers clear and satisfying holes in metal, wood, and also plastic.

  • Sometimes finding a quality drill bit for multiple-functional use can be a far cry. Luckily, this drill bit offers a wide range of uses, starting from metals to all the way wood or plastic. Additionally, you will get a better grip on the working surface and be able to boost up the rigidity.

  • The 1/4″ bit breaks with the slightest application of pressure. Sometimes you have to use water on metallic surfaces to reduce the overheating issue.

Best Budget

Hymnorq Metric M35: Best Drill Bits for Iron

  • The bits have a rigid surface for drilling into all forms of steel work-space.
  • Having a self centring edge point, the bits stay straight on uneven material.
  • A wide range of size options provides easy access to metals, plastic, and re-drill wood.
  • Able to penetrate into materials with rough surfaces due to its 67 plus hardness.

Hymnorq Metric M35 is another industry-leading cobalt steel drill bit, having all the specs you will ever need. Turns out, prices are low, and features are way above the normal price range. It has a molybdenum and cobalt combo, which adds both power and rigidity. Professional craftsmen will never feel bored using its awesome drilling performance.

The bit-set starts from 1.5 mm all the way to 6.5 and fits almost all power tools. Surprisingly, adjusting the rpm settings can make help penetrate into any steel working surfaces. However, you need to download the user manual to help you guide through the variation in surface hardness.

  • What kind of drill bit for cast iron is kinda on the rough side if you don’t know the variation insides and the hardness level. However, the Hymnorq Metric M35 bits have a hardness level greater than 67, giving you better performance on all surfaces. It is also highly durable with zero edge chippings.

  • There are hardly any drawbacks to this bit, except the pricing. Then again, the smaller ones tend to bend but drill flawlessly.

How to Drill perfectly through Cast Iron?

We know cast iron is a brittle substance and very few metals will dig it. But if you have the best drill bit for cast iron then you are only one step behind, that being said, you should come to know how to drill the cast iron. Read between the lines below to learn it.

Many people advised previously to use lubricant while drilling. But experts never opt for it. Because cast iron substance includes carbon content so to cut through it seems viable without using lubricant. On the other hand, lubricant causes issues like it messed up with debris.

That means, it makes the debris to cling inside the metal and debris stuck inside of it. Another hack is, if you are drilling a few holes then this would be okay to some extent. But while drilling plenty of holes then it turns out to be a mess.

How to drill through cast iron

Now follow these steps:

1. Mark the location by making a dimple: You should know your target while making holes, right? So marking your location will enhance your efficiency to a great extent, to do so, use a hammer and a center punch then move with your marks.

2. Attach the right drill bit: You need to measure the size of a hole which you will bore. Afterward, fix the bit which will fit the most. However, when you will drill a hole where a screw will remain then a little shorter will do the job.

3. Take support while needed: You may need to brace the cast iron when it is not connected to the stationary object. Here you will definitely need support for example, a table vice in order to hold two sides of the object.

4. Hold your drill bit to the upright, and slowly fire the trigger: Most of the novice users do this fault like they don’t hold the drill to the upright side. Afterward, pull the trigger abnormally, don’t do it.

5. Remove the metal debris: Finally, it is high time to hold the trigger down then smoothly take out the drill back and forth. Following this process, you can easily remove the debris.

Key features to pick the Best Drill Bits for Cast Iron

A regular drill bit is worthy to cut through cast iron metals. However, the cheap one comes with the shortcomings and they barely offer to bore more holes without using lubricant. Turns out, the lubricant messes up the debris.

Aside from a good bait of drill bits for cast iron you can choose some additional stuff as well. For example, the cast iron doesn’t bother you with the vibration so you can easily dig into it. So the only downside is with managing the debris, as we said before. To make it manageable then we will ask you to get your hands on black oxide drilling bits.

On the other hand, you can also try a cobalt steel drill bit as well. Because it is far more tough compared to the regular drill bits and almost impossible to break or twist.

By the way, if you want to go one step ahead from all types of cast iron drill bit then the Titanium nitrite would be the best overall. Here, we will recommend you with the DeWalt Titanium Drill bit for you. Do you know why it is such a durable drill bit? Well, it is applied with the TIN coating so it lasts six times longer and lasts longer than any average drill bit.

FAQs on Best Drill Bits for Cast Iron

Can Cast Iron be drilled and tapped?

metals and chips are the by-product of cast iron. However, they are small but strong enough so the drill tip will break down. Here is why, when your drill will go through the hard spot, then focus more on the drill tips. Making sure to tap the hole will be a breeze to save the guts. 

Is cobalt or titanium drill bits better?

While comparing Titanium drill bits and Cobalt drill bits, the Cobalt seems better to deal with the harder materials (For example: cast iron). On the other hand, Titanium works better to serve the softer objects like plastic, wood and light metals. 

Will a Sawzall cut cast iron pipe?

Sawzall is a type of reciprocating saw which is good for cutting hard metals except rocks. So you may consider it to use against PVC and any sort of metals. For the wood cutting, it takes the minimum effort and time to cut through smoothly. 

What’s the best way to cut cast iron?

You can cut cast iron in many ways, but when it comes to cutting with the precision under minimum human effort then using drill bits would be a wise decision. However, it is less powerful compared to any diamond saw blade but it is far more accurate and more importantly, it won’t mess with the debris. 

Take the best cast iron drill bit

Hopefully you have come to know what kind of drill bit for cast iron is good for you. The cobalt is generous and affordable, when you are not worried about getting the maximum force against the cast iron then this would be great. However, if you look for the best in this business then no drill bit can offer the same like DeWalt Titanium Drill Bit for cast iron.

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Sam Morgan is a general contractor based in Charlotte, North Carolina. He does home renovations, extensions, landscaping maintenance, and general handyman jobs for homeowners. He is also the part-time content writer at Machine Handyman and a lifelong tools enthusiast. Sam loves hand tools, power tools, machinery, and DIY gadgets of all shapes and sizes! He is always researching the different types of home improvement tools that will get the best results. This site will cover products like power drills, air compressors, saws, nail guns, screw guns, grinders, cutting tools, and many more.

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