Best Cobalt Drill Bits: In 2020 [8 Top Picks]

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This review provides a summary of the characteristics and performance of the Irwin 5% Cobalt 29-drill bit set. These drill bits are manufactured using heavy-duty web construction for strength and durability. They are made of 5% cobalt for higher heat and abrasion resistance. The sizes sold in this set are 1/16 inch - 1/2 inch in 1/64 inch increments. They also have split points to minimize walk. 

These drill bits from Irwin will be a disappointment if you purchase them with the intent of drilling into hardened steel, or stainless steel, however, they are good for drilling thicker wood, hard plastic, plexiglass, aluminum or mild steel. If you are drilling into metal, you will have less risk of breaking a drill bit if you make an indentation in the metal before you start. When you start to drill in the metal, you should go slow, use plenty of lubricants and press down as you go.

You can expect decent quality from this Irwin drill bit set. However, the bits will break if you don’t control the speed. The harder the metal, the more trouble you will have. These bits don’t do well with hardened or stainless steel. This set of Irwin M-35, 5% cobalt bits are made in China and aren’t as durable as the Irwin 8% cobalt bits, which are made in America. 

Verdict: If you don’t try to drill hardened steel or stainless steel, these drill bits will be a good set to own. Take care of them, and they will last a long time. If you do have trouble, the manufacturer is quick to assist. 

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These Drill America drill bits are jobber length. They are made of 5% cobalt steel and coated with gold oxide. They include sizes 1/16” – 1/2” in 1/64” increments. Cobalt increases the toughness and heat resistance of the drill bits at high temperatures. Gold oxide acts as a lubricant and protects the drill bits from wear. 

These are split point drill bits that have straight angled (135 degrees) tips. This feature prevents the drill bits from walking or slipping when you start to drill. If you are drilling metal, you should mark the metal or make a small indentation in the metal, even though the bits are split into the point before you start to drill. That will prevent slippage before the drill bit has a chance to enter the surface of the metal. It will also reduce breakage.

The quality of the Drill America drill bits is good, and the performance is better than average. Good for drilling through wood, plastics, and mild steel. Hardened metals are difficult for a 5% cobalt steel drill bit. The harder the metal, the more difficulty they will have. Drilling in metal should be at a controlled speed with constant pressure and use plenty of lubricants.

The gold oxide finish is a coating and will wear off quickly, especially when drilling metal. If you sharpen the bits, the gold oxide coating will disappear.

Verdict: This set of Drill America 5% cobalt drill bit is a good set, and they will last a long time if used correctly. They are best used for wood, plastics, and mild metal. 

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Step drill bits are designed to create a certain size hole by increments or to increase the size of an existing hole to a larger hole, by gradual steps. A step bit will take a hole from 1/4-inch hole to a 1-inch hole by steps, or increments. The bits are marked so you can stop at the size you want. They are also useful for making various size holes without changing bits.

The smaller bits are designed to be used on thinner materials, while the larger bits work better on thicker materials. However, they each work either way.

They come with shanks sizes 1/4-inch, 3/8-inch, and 1/2-inch to be compatible with chuck sizes.

These CO-Z high-speed steel bits are coated with titanium, and they are supposed to keep their shine for years. The titanium coating wears off quickly, especially if you are drilling metal. However, that doesn’t mean that they aren’t good step drill bits. They are made with 5% cobalt, which does improve the performance of these drill bits in metal. They are good for wood, plastic, Plexiglas, aluminum, sheet metal, or non-hardened metal. They are not made for use with hardened steel.

These are non-walking drill tips. However, if you are using the bits to drill into metal, you should always make a pilot point or a dimple in the metal before you start to drill.

Verdict: This set of high-speed cobalt steel drill bits is a good set. However, they are not made for or recommended for use with hardened metal. 

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This set of drill bits from Dewalt is designed for use with metals. The Dewalt bits are produced from using industrial strength 8% cobalt construction to improve durability and performance. The bits are compatible with drilling through harder metals.

They drill faster compared to any other drills. Drilling through hardened metal is different from drilling through woods. We recommend using a slower speed, plenty of lubricants, and steady consistent pressure to drill hardened metal. These are advertised to drill through stainless steel. However, stainless steel is very hard, and this excellent set of Dewalt drill bits will take time to drill through stainless steel.

The cobalt construction of these bits allows them to stay cooler during drilling through harder or thicker steel. However, the friction will still cause them to heat up and need to cool down during the drilling process. You can add more lubricant on the bit from time to time to cool it down if it starts smoking from the heat.

The typical 135-degree angle and split point design allow optimal performance with less force. The set comes with bit sizes from 1/16” through 1/2” in 1/64” increments.

The pilot point design prevents breakthrough lock-ups.

Verdict: Optimal performance of these drill bits makes them one of the best we’ve seen. A set of these will be an asset to your tool collection!

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This set of 8% high-speed cobalt steel drill bits are graduated in size from the smallest at1/16" to 1/2" in 1/32 increments. The high heat treated hardness is 68-70 on the Rockwell Hardness Scale. They are made with the typical 135-degree angle, split point design, which decreases the amount of force required while drilling and prevents walking. The tri-flank shank design prevents slippage in the chuck.

As with all drill bits, if you are drilling through hard metal, you must take care to set it up by locking everything down. Going through creating a pilot point or a small indentation in the metal, where you intend to drill, apply a generous amount of lubricant, and start slow.

Apply consistent speed and force and be prepared to back off if it stops or starts smoking. If it starts to smoke, you should stop the drill and squirt water or add more lubricant. Best for use with a drill press. If you use a cordless drill, make sure you hold the drill at a right angle from the point you’re drilling. The smaller bits tend to be brittle.

Verdict: Drill Hog has produced a great set of drill bits with these. They seem to stay sharp longer than most, offer all the sizes you need, and they used all the best designs for high performance and long life. They also back their products with great customer service.

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These are premium cobalt, high-speed steel drill bits which are good for drilling 1/2” to 1” holes in wood, aluminum, copper, and plastic as well as sheet metal and other mild metals. They have black nitride and gold-titanium dual coating finish, which holds lubricant for smooth drilling. This coating is durable almost 80% than coating free, and compared to regular black enamel finish, it is more corrosion-resistant. At the tip, you'll find there a 135-degree split point that allows these drill bits to drill faster without having to apply pressure. The ½-inch shank (Shastri-flatted) ends, which fit into a 3-jaw-chuck securely, that eliminate slippage. This set has 8 pcs. of S&D drill bits. The sizes are typically 9/16 inch, 5/8 inch, 11/16 inch, 3/4 inch, 13/16 inch,7/8 inch,15/16 inch, and 1 inch. 

These drill bits are not made for heavy-duty projects, but if you use them correctly, they will last for a long time. The black nitride coating with gold titanium will wear off quickly, especially if you use them to drill in metal. However, these bits are still a good choice. There may be a few burs to buff off of the drill bits before using, and the holes they drill may need to be cleaned up. But these are minor flaws from the manufacturer, which you can fix instantly. They will not do well with stainless steel.

High-velocity cobalt steel is the main ingredient of these drill bits, which makes them harder. They should last a long time. Although the design is not to walk, you should always make a mark, or dimple in the metal before you start. It will prevent the bit from slipping and possibly breaking when you start to drill.

Verdict: You will observe that these drill bits may lack great manufacturing quality or high-quality control standards. A fast assembly line process implied to manufacture them and missing of flaws identified. However, HSS steel construction with cobalt makes them a practical choice.

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The Craftsman cobalt drill bits are advertised for use on drill presses and stationary machines for all metals, including hardened metals. They also work with corded and cordless drills. You will need to use a slower speed, plenty of lubricants, and steady consistent pressure to drill through hardened metal. These cobalt drill bits are designed to perform better. However, the stainless steel is very hard, and even the best drill bits take longer to drill through hardened metals.

This drill set is better for use with wood, plastics, Plexiglas, aluminum, and mild metal.

The set contains 21 drill bits in a size range from 1/16-inch to 3/8-inch. They are made with 5% cobalt for higher heat and abrasion resistance and added protection from wear. The split top tip eliminates walk and lets the tool cut into metal with the first rotation. When using smaller bits that tend to break easily, we recommend making a pilot point or a dimple where you plan to drill. It also helps to keep your drill at a right angle to the hole you’re drilling. Hold it steady and apply consistent pressure.

We hesitate to recommend these Craftsman drill bits to drill hardened metal. Although they are made with cobalt, you will need to work carefully and use a lot of lubricants to get through hardened steel. It’s a slow process that requires patience.

Verdict: This set of Craftsman drill bits are of decent quality, especially for non-metal uses. Drilling into hardened metal was a frustrating process for these drill bits.

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The Bosch Cobalt drill bits are well known for their ability to drill through the hardest of metals, and we found that to be true with this set. They cut cleanly and accurately through stainless steel, cast iron, and other high-density metals. Solid and reliable, these high-performance drill bits are ideal for higher drilling temperatures in hardened steel. Always protect your bits by using lubricant when drilling, especially in hardened metals.

Drilling in hardened metals requires a slower drill rotation and plenty of lubricants. Use steady pressure and keep your drill at a right angle to the hole you are drilling. Most of the fails we’ve seen are caused by using too much force or faster speeds. 

This set features a split top tip for accurate starts, where the bit cuts through metal on the first rotation. For smaller drill bits, you should mark the metal with a pilot point to prevent breakage. 

The three flat shank design allows the shank to hold securely in the chuck of your drill and prevents slipping on shank sizes 3/16” and above. 

The bits are laser marked to clearly indicate the bit diameter. The set includes the following sizes: 1/16-inch, 5/64-inch, 3/32-inch, 7/64-inch, 1/8-inch, 9/64-inch, 5/32-inch, 11/64-inch, 3/16-inch, 13/64-inch, 7/32-inch, 15/64-inch, 1/4-inch, 5/16-inch, 3/8-inch, and 1/2-inch. 

Verdict: The performance of the Bosch Cobalt Metal Drill Bit set is exceptional. You can’t go wrong with this set.