M35 Vs M42 Cobalt Drill Bits, which one to choose?

M35 Vs M42 Cobalt Drill Bits, one will find the information on the cobalt drill bits and their type. Also, this article will illustrate the information regarding the difference between M35 and M42 which are two types of cobalt drill bits.

Specifically, both of the drills have a difference in the amount of cobalt they made out of. One type has more cobalt than the other one. Because of this difference, they have some other major differences. Furthermore, have a look below to know more about the topic.

M35 Vs M42 Cobalt Drill Bits

M35 Vs M42 Cobalt Drill Bits

Working in the garage making something or fixing something, one must have an encounter with the drill bits. Specifically, drill bits are the most versatile device which is helpful in most of the work in household repairing, rebuilding, at a garage, and many places. In case one does not have an encounter with this extremely useful device, it is a cutting tool that is used to remove materials or create holes. One can use those devices to drill surfaces of different materials.

Luckily, one will find the various options in the market in drill bits to make a hole in different types of surfaces. Some of the bits are dedicated to metal or wood, and some of the drills can be used on any type of surface. Moreover, we will discuss the more common drill bits namely cobalt in this article. It is made out of steel alloy but has 5% to 8% cobalt. Here is the category of this drill in two types depending on the percentage of cobalt.

Specifically, the Cobalt drill bits are made out of M42-grade cobalt or 35-grade cobalt steel. If the drill bits have 5% of cobalt then they will be called M35 grade cobalt steel bits. On the other hand, if the drill bits have 8% of cobalt then they will be called the M42 grade cobalt steel bits. Mainly, the manufacturer or the inventor designed the bits with cobalt to make their high resistance to heat. Let’s know about the more differences they share to be clear on the topic.

Table: The melting point of M42 is 2853 degrees F

M35 Cobalt drill bitsM42 Cobalt drill bits
It contains 5% of cobalt in it.It contains 8% of cobalt in it.
The melting point of M42 is 2723 degrees FThe melting point of M42 is 2853 degrees F
Expensive but a little less than the M42.It is expensive to buy.
Extremely resistant to heat but less than the other one.Extremely resistant to heat.
Too sharp that it can drill a hole into any metal.Sharper than the M35 because of more cobalt.
Extremely durable.Not as durable as the other one because of more cobalt.

These are the differences between both types of shares on performance. Since they are of the same type one cannot expect many differences here. Let’s see the features and similarities both the type shares as cobalt drill bits.

IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel (Check latest price)

Metric M42 8% Cobalt Twist Drill Bits (Amazon)

Heat resistance

The cobalt is manufactured to tackle the high heat of the traction of metal to metal. It is known to all that anything that has traction will produce heat even fire. Our ancestors used to make fire with the stone to stone traction. Now one can imagine how much mass it will create from the metal to metal traction. In drilling, if the driller material is not highly resistant to heat, it will lose its shape as well as performance. In that case, the cobalt M35 and M42 both are highly resistant to heat.


As for the performance of these two, we can surely say that both of the drill bits are two of the best in the market. Specifically, these are designed to deal with heavy-duty drilling in tough materials like iron. Most of the tough and heavy material is nothing with these two drillers. Mainly, the M42 will work a fantastic job to drill a hole in the heaviest surface.


As we mentioned that these drills work excellent with most heavy-duty materials, one can imagine the versatility of these drills. Owning any of these will do every kind of job one will have to do in their lifetime.

Overall, both of the drills are extremely amazing to use for day-to-day use or in heavy industrial use. Considering the need and use of the user they can choose any of the one these two.

What is the working geometry of Cobalt M35 and M42 dill bits?

To work on the metal surface or any surface with perfect output one will have to know the geometry of the bits. As for the Cobalt M35 and M42, the geometry will be,

Workpiece materialPoint angleHelix angleLip relief angle
Aluminum90 to 13532 to 4812 to 26
Brass90 to 1180 to 2012 to 26
Cast iron90 to 11824 to 327 to 20
Mild steel118 to 13524 to 327 to 24
Stainless steel118 to 13524 to 327 to 24
Plastics60 to 900 to 2012 to 26

What are the different Cobalt drill bits available in the market?

Specifically, the cobalt drill bits are two types according to the building material. One is M35 cobalt drill bits and another one is M42 drill bits. Besides, according to the shape and size of the drill bits, there are some other types one can consider.

Twist Cobalt Bits

The most common and used bits are the twist cobalt bits and this is the most preferable one. This can be used in different types of surfaces and materials easily and effectively.

Counterbore cobalt bits

These different bits have a flat bottom and a hole in the middle of the bits. The design of the bits helps the driller to cut the surface thoroughly and perfectly. These are perfect for material surfaces of plastic and wood. However, these are not suitable for metal surfaces of any kind.

Cobalt step drill

Specifically, these are perfect for metal surface drilling. One can easily drill up to 0.25 inches holes in different types of surfaces. Also, it is easier to drill holes of different diameters. Amazingly, this is an extremely versatile drill bit that can be used in different types of work. One can use it with another device to create holes in different surfaces. One can also use it in the vehicle body to create a smooth hole.


Drilling is an important job when one is making something using metal, wood, plastic, or things like that. Also, it is helpful when one is repairing something. In search of the best drilling bits, one will fall to the cobalt which has two different types one is M35 and the other one is M42.

Both of the options are extremely useful and reliable. With extreme heat resistance, one can easily use them to create a hole in the metal surface. Hopefully, the discussion above on M35 Vs M42 Cobalt Drill Bits helped one to clarify the confusion.

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