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M7 vs M42 Drill Bits: Choosing The Right One

With thousands of drill bit products in the market, choosing the right one is difficult. Especially if you’re stuck between two popular choices: the M7 and the M42. But don’t worry, we will help find your perfect drill bit match.

M7 Vs M42 Drill Bits: what are the differences?

The basic difference between them is their composition. M7 is composed of Hi-Molybdenum M7 and M42 is composed of 8% Cobalt. That’s why M42 is stronger and more brittle than M7. Since M42 has a higher melting point than M7, M42 is more heat resistant. M7 is best for heavy construction drills and M42 is best for drilling strong metals.

These are the differences between M7 and M42 drill bits in a nutshell. However, if you want an in-depth description of these two drill bits and their features. Go through the comparison prepared, just for you.

Are you ready?

M7 Vs M42 Drill Bits: What Makes Them Different

If your project is to fix a wooden stair riser, the HSS (High-Speed Steel) drill bit would be the best option. But when it comes to stainless steel and hard metals, a standard HSS will not suffice.

The drill bits used to cut through drill stainless steel or hard metals are called Cobalt or Molybdenum drill bits. These drill bits are composed of a certain percentage of cobalt. Which can help you cut through the metals quicker than casting a spell.

There are many options for buying a Molybdenum drill bit out in the market.  Two popular options among them are M7 and M42.

Here’s a quick comparison between M7 and M42 for your ease of understanding:

M7 Drill Bits M42 Drill Bits
Contains more Molybdenum than M47 Contains less Molybdenum
The melting point of M7 is 5000 degrees F The melting point of M42 is 2853 degrees F
M7 is not water-resistant M42 is water-resistant
Does not contain Cobalt Contains 8% Cobalt
Less expensive More expensive

Before we jump into the direct comparison, let us first know a bit about each of the drill bits.

What Are M7 Drill Bits?

The M7 drill bits are made by Hi-Molybdenum M7. This drill bit is specially used for heavy construction drills. It offers the flexibility of razor-sharp tips. So you know which drill bit can endure the heavy workload.

Here’s a list of the top 3 M7 drill bits we think will be best for you when working with stainless steel and hard metals-

Product 1
Product 2
Product 3


With a melting point of 5000 degrees F, the M7 drill bits are extremely heat-resistant. It is also wear-resistant which contributes to its extended life. The carbon and vanadium components of the bit also make it stronger and more durable. 

The best thing about M7 drill bits is the abrasion resistance which makes them suitable for semi-hard steel and machining.


The M7 drill bits are not water-resistant like that of the M42 drill bits. M7 does not have cobalt in its composition as a result it is not as strong as the M42 bit. 

There are also some issues with the consistency of quality of the drill bit performance. With every sharpening of the drill tips, the performance quality reduces.

What Are M42 Drill Bits?

M42 drill bits are drill composed of 8% cobalt. This cobalt gives the strength of the drill an extra boost. As a result, this bit can be used to drill the toughest surfaces. That’s right! You can drill titanium, cast iron, hard alloys, abrasive metals, and even stainless steel. 

Whether you’re drilling composite deck screws or wood screws, M42 drill bits make it effortless.

Here’s a list of the best M42 Cobalt drill bits we think will work best for you when dealing with stainless steel and hard metals:

Product 1
Product 2
Product 3


The cobalt composition of M42 helps it cut through the strongest surface. Cobalt also increases the water and heat resistance of the bit. This increases the durability and gives the drill bit a long life. Plus its melting point is 2853 degrees F. So the M42 drill bit can be used in any heated working condition. 

The tip of the drill bit is also razor-sharp and thus can be used at a higher cutting speed. This makes the drilling process effortless. 


The only drawback of the M42 drill bit is that it is more expensive than the M7 due to its composition.

Besides that, the M42 cobalt drill bit also has issues regarding the tip sharpness. Once you sharpen the blunt edges, the cutting tips will not be the same.

The Verdict

M7 and M42 are both unique drill bits that offer various advantages and disadvantages. 

If you have a project that includes heavy construction, you better rely on the M7 drill bit. With its extended and durable life, M7 will be a great support. 

On the contrary, if the project you are working on involves a heavy or hard metal, M42 will be the best for you. Because of its strength, working with hard and semi-hard metals becomes easier.

Whether you’re building with syp or spf, choosing the right drill bit is up to you. If any drill bit meets your requirements, definitely go for it!


Which drill bits are the strongest?

Among M7 and M42 drill bits, we’ll have to say M42 because its cobalt composition makes it stronger and durable. M42 can drill the toughest of surfaces including titanium and hard alloys. You can get any DIY home improvement task done with the help of these tools. 

What is the difference between M35 vs M42 cobalt drill bits?

The basic difference is M42 has a higher percentage of cobalt than M35. M42 drill bit has 8% of cobalt whereas M35 drill bit has 5% of cobalt. The more cobalt in the composition, the stronger the drill bit. 

Do I need to use cutting oil with cobalt drill bits?

Cutting oil is definitely a good idea if you want to extend your drill life. Cutting oil lubricates the drill bit. As a result, it reduces friction and heat to a certain extent. Cutting oils are necessary for drilling metals.

Signing Off

M7 and M42 both drill bits have great performance when drilling through tough surfaces. By now you will know all the differences between M7 and M42.

So, from our comparison of M7 vs M42 drill bits, let us know which one of the two drill bits are you going for.

Till then, happy drilling!