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Cobalt vs. Carbide Drill Bit

High-speed steel drill bits are sometimes ineffective at drilling tough metal to produce spectacular results. To keep your manufacturing company at the top, you need to acquire durable and efficient drill bits, such as carbide or cobalt, to work on tough materials. 

You have probably heard that solid carbide drill bits are the most efficient, and cobalt drill bits are durable. This simple explanation is not enough to make an informative decision on which one to buy. SCTools is committed to helping you machine better, and we will give you a detailed breakdown of these two drill bits and help you choose the ideal one for your machining needs.

What is Unique About Solid Carbide Drill Bits?

Carbide drill bits are made of tungsten carbide, a combination of carbon and tungsten. This mixture helps increase metal cutting speeds and feeds, giving it a durable tool for cutting edges. Solid carbide drills are efficient in high-speed drilling and are used on fiber-glass reinforced plastics and hard, non-ferrous heavy metals. 

Carbide is the hardest and most brittle drill bit in use today and gives a magnificent finish. Carbide drill bits are not suitable for hand tools such as impact drills or cordless drills but are generally ideal for high-production drilling.

What is Special About Cobalt Drill Bits?

Cobalt drill bits are primarily made from a 5–8% cobalt concentration and high-speed steel. This combination improves the heat and wear resistance of the drill bit, making it durable. Cobalt is added to the stainless steel alloy (Iron and Carbon) during formation, enabling resharpening without losing the drill bit’s cutting quality. Cobalt drill bits are best used on tool steel, stainless steel, and other hard ferrous metals. 

Carbide Drill Bits vs. Cobalt Drill Bits Pros

As we have seen, both drill bits are made from high-grade materials and perform well. But in terms of strength, solid carbide drill bits are superior, with a hardness of 75 HRC and cobalt’s hardness of 65 HRC on a Rockwell scale. The table below compares the pros of cobalt and carbide drill bits. 

Carbide Drill Bits 

Cobalt Drill Bits

Last longer, allowing drilling of over 1500–2000 holes before needing resharpening

Easily resharpened after repeated use

Harder and more heat-resistant than cobalt, making them more chip-resistant

Less expensive than carbide but does not match its effectiveness

Can work at very high speeds improving cycle time and decreasing manufacturing speed

Have self-centering points, which relatively reduces cycle time

Carbide drill bits hardened steel eliminates the need for peck drilling

Drills five times their shaft size before needing pecking (increases wear)

The toughness allows the drill bit to cut coolant-through holes. The lower temperatures introduced reduce heat treatment of the drilled part and drill wear 

Cuts soft and hard materials 

Carbide Drill Bits vs. Cobalt Drill Bits Cons

Carbide and cobalt drill bits have an ultimate breaking point that can lead to chipping and ineffective functioning if not used properly. Overall, both drill bits get the work done with minimal cons, as shown in the table below.

Carbide Drill Bits 

Cobalt Drill Bits

More costly than cobalt 

Do not last as long as carbide drill bits hardened steel requiring resharpening after 100–200holes

Harder to resharpen compared to cobalt

Cannot work as fast as the drilling speeds of carbide drill bits

May need replacement once it is blunt, but its durability decreases the frequency of replacement

Can easily chip when drilling extremely hard material in temperatures beyond the specified range

SCTools recommends carbide bits as the ideal drill bit to give your manufacturing company the cutting edge it needs to offer an impressive finish to products. You are assured of a masterful and splendid finish with a carbide drill bit that increases production speed and reduces costs. 

TechTalk SCTools Drilling Applications TechTips QR Code If you have any questions about carbide cutting tools, end mills, drills, etc. be sure to reach out to us @ or call us at (877)737-0987. We help you machine better! 

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