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Why Is Diamond Not Used for the Machining of Ferrous Material?

Why Is Diamond Not Used for the Machining of Ferrous Material?

One perhaps not so frequent and common question, but certainly worthy of our attention, is: Why is diamond not used for the machining of ferrous material?

The only accurate and precise answer to the question posed would be: Although diamond tools are widely employed in cutting non-ferrous materials for high-quality mirror surfaces – they can’t be used to cut ferrous materials.

It is because of diamond’s (carbon’s) strong chemical affinity with iron, which causes excessive tool wear.

As with most things, one question begets completely new questions, and when this topic is on point, it is necessary to first guide you in basic stuff like what ferrous metals are and what are not. Also, there are many more things you can learn in this article.

Let’s investigate the topic and clarify any ambiguities in our original answer!

What Does The Term “Ferrous Metal” Mean?

We will start today’s topic by clearing up all ambiguities related to the term ferrous metals.

Ferrous metal is any metal with magnetic characteristics predominantly made of iron. The hardness, durability, and tensile strength of ferrous metals are well recognized.

The strength of ferrous metals is also well recognized and employed.

Their qualities make them ideal for usage in both the industrial and architectural sectors for projects like skyscrapers, bridges, railroad projects, and automobiles.

Due to their magnetic characteristics, ferrous metals are also commonly employed in many appliances and engines.

On the other hand, ferrous metals have a high carbon concentration, making them more prone to rusting; stainless steel is an exception owing to its chromium presence, as is wrought iron due to the purity of its iron component.

Ferrous metals are employed in practically every industry, including the production of shipping containers, industrial pipelines, vehicles, railroad tracks, ships, and various commercial and household items.

Some examples of common ferrous metals are:

  1. Alloy steel
  2. Carbon steel
  3. Cast iron
  4. Wrought iron

Durability, high tensile strength, magneticity, poor corrosion resistance, silver color, recycling ability, and electrical conductivity are all desirable ferrous metal qualities.

However, due to the extensive range of alloying elements that affect their properties, it is difficult to identify common attributes across ferrous metals.

Many ferrous metals, for example, are thought to be magnetic; however, this is not true for all ferrous metals.

Ferrous metals, such as cast iron are solid but fragile. Low-carbon steel, which is also a ferrous metal, is exceptionally soft and pliable due to its lower carbon content than cast iron.

Depending on the specification, iron and steel are carbon-based ferrous alloys that can contain several additional components ranging from aluminum to vanadium.

The mechanical qualities of these metals are commonly used to justify their selection. Engineers and designers may be interested in yield strength, durability, flexibility, weldability, elasticity, shear, and thermal expansion.

Ferrous metals share several fundamental features, such as rust resistance and magneticity.

Among the common ferrous metal qualities are:

  1. Durable
  2. Tensile strength is high
  3. Excellent electrical conductivity
  4. Corrosion resistance is low
  5. Recyclable silver color
  6. Typically they are magnetic

Let’s take a look at the main differences between ferrous and nonferrous metals!

What Is The Difference Between Ferrous And Nonferrous Metals?

To best understand the differences between ferrous and nonferrous metals, it is necessary to go back to the distant past and the charms of history!

The straightforward explanation is that ferrous metals contain iron, whereas nonferrous metals do not. The more detailed response is that ferrous and nonferrous metals each have specific characteristics.

These characteristics dictate the applications they are most suited for.

Nonferrous metals have been utilized since the dawn of time. Copper’s discovery about 5,000 BC heralded the Stone Age’s end and the Copper Age’s start.

The Bronze Age began with the later development of bronze, an alloy of copper and tin. When iron manufacturing became prevalent around 1,200 BC, the usage of ferrous metals began.

This was the start of the Iron Age. Simply speaking, the presence of iron distinguishes ferrous metals from nonferrous metals. Nonferrous metals do not contain iron, whereas ferrous metals do.

Nonferrous metals have been in use far longer than ferrous metals. The Bronze Age began with the development of bronze, a nonferrous alloy of tin and copper.

With the arrival of the Iron Age, approximately 1200 BCE, the usage of ferrous metals became more widespread.

Since then, humans have assigned uses to both metal kinds depending on their respective strengths and limitations.

Why Is Diamond Not Used For The Machining Of Ferrous Material?

Machining ferrous metals using diamond tools is one of the most significant areas of ultra-precision machining since it is impossible to create a nanometric surface with diamond tools alone.

The wear mechanism and techniques for tool wear reduction addressed in the literature are reviewed. However, if you don’t have any literature, don’t worry; this article will explain everything you need to know.

Publications have demonstrated that ultrasonic vibration cutting and workpiece surface modification have more significant impacts in enhancing tool life in diamond cutting of ferrous metals compared to existing tool wear and surface polish methods.

However, compared to ultrasonic vibration cutting alone, the combination of the two techniques does not enhance the surface polish or the tool wear reduction.

Research shows that replacing diamond tools with nano-grained CBN and developing fresh diamond-cutting materials can extend tool life.

Diamond cutting tools are not advised for machining ferrous metals due to the following reasons:

  1. High tool hardness
  2. Tool material’s chemical affinity for iron
  3. Inadequate tool toughness
  4. Work material with a high heat conductivity

Diamond is essentially pure carbon, with atoms organized in a cubic crystal structure that makes it extremely strong. A diamond is made up of a single giant crystal.

If you are not good at chemistry, don’t worry, we will explain this as simply as we can!

When you cut steel with a diamond, the carbon atoms react with the iron to generate Iron Carbide at higher temperatures (more than 700 degrees Celsius) (Fe3C).

The carbon atoms in the crystal structure effectively divorce their old Carbon companions, get wedded to some new Iron partners, and the crystal structure collapses, rendering the tool unusable.

Related Read: Is Steel Harder Than A Diamond?

The Benefits of Diamond Machining

Diamond machining provides several advantages, the most important of which are:

1. Excellent Aluminum Machining

Diamond tools can resist extremely high cutting rates and temperatures.

As a result, diamond methods are frequently utilized in the mass manufacture of aluminum components. When cutting aluminum, a single diamond inlay can outlast many carbide tools.

2. Production of Hard Alloys

A more challenging substance will always be able to cut a softer one.

Diamonds are highly beneficial for machining carbide, ceramics, and other materials with high hardness criteria since nothing is more complex than diamonds.

3. Polishing With Diamonds

Transparent materials such as glass, polycarbonate, and PMMA are polished using diamond cutters. This is because the tool’s tip contains excellent diamond grains.

4. Durability

A diamond tool insert is 30-50 times more durable than a carbide insert.

5. The Surface Polish

When using diamond for high-quality machining, you may get a superior surface finish than any other type of conventional tool.

Diamond tools, in essence, introduce a little grinding element into machining.

Now that we’ve done the benefits, it’s time to look at diamond machining methods!

Diamond Machining Methods

The bulk of diamond-based machining processes is considered grinding and polishing procedures. However, you may use two ways for CNC equipment that is closer to cutting than abrasive processing.

1. Single-Point Diamond Turning

SPDT is a process that is very similar to simple turning, except that the tool is a diamond-tipped cutter. Furthermore, the production system’s stiffness must be substantially greater.

That implies shorter fixture lengths, shorter tool supports, and less vibration.

SPDT is highly beneficial for making optical lenses since they are primarily revolution pieces and can be easily mounted on a lathe with single-tip diamond inserts to get clean, transparent surfaces.

2. Single-point Diamond Milling

The cutting tool and processing parameters are the fundamental difference between single-point diamond milling and conventional milling. A mill with diamond-tipped inserts is used.

This mill, mounted on a 5-axis machining center, is ideal for treating complicated surfaces composed of glass, PMMA, and polycarbonate.

A high-speed rotating diamond mill with a low cutting feed and a generous lubrication supply can produce the most refined surface polish for automobile lamp lenses, light guides, and bespoke window panes.

However, it is critical to realize that vibration will damage all surface quality at once.

Some SPDM procedures involve machining solely in one direction to enhance piece quality (the mill processes a path and then returns to the beginning side of the workpiece for a stepover movement, ensuring that the cutting force is constantly in one direction).

What Is The Use of Diamonds In Cutting Tools?

As mentioned in the subtitle related to benefits, diamonds play a role in the cut. So let’s take a quick look at how and why!

Because diamonds are the most complicated element and can cut through rigid materials, they are widely utilized in cutting tools. Diamonds have long been used as a cutting tool.

Diamonds are divided into jewelry manufacture and industrial-grade diamonds for industrial cutting instruments.

When diamonds are utilized in industrial instruments, the four Cs of diamonds, cut, color, clarity, and carat, are not as visible. You only need little parts.

Small diamond particles are ideal for embedding in saw blades, grinding wheels, and drill bits.

Diamonds have been successfully employed on saw machine edges, circular blades, and even diamond saw blades. Diamond-equipped machines outlast those with regular saw blades.

Also, diamond is used in cutting tools for a variety of purposes. They are used in these industrial cutting tools because of their hardness.

Another benefit is its high melting point and extended life.


As we already mentioned – A diamond is made of carbon, the most challenging material on the planet. Because of its hardness, it is excellent for cutting various materials, notably difficult-to-cut metals.

A diamond can even scratch Tungsten, which has a Mohs hardness rating of 9.5 on a scale of 1 to 10. On the Mohs scale, a diamond is a 10.

Because diamonds have a high melting point, they are ideal for cutting metal and are used with industrial cutting equipment.

This implies it can withstand a great deal of heat and pressure.

A diamond has a melting temperature of 2700 degrees Celsius (4892 degrees Fahrenheit) and a burn point of 800 degrees Celsius (1472 degrees Fahrenheit).

Related Read: Can You Melt Diamonds? Do Gems Melt?

Withstand High Temperatures

While carbide and high-speed steel are cutting tools, diamond/Carbon Boron Nitride CBN tools offer outstanding hardness and heat diffusion.

Polished diamond/CBN tools have a sharp cutting edge and give excellent accuracy over a long period. Diamond is utilized in cutting tools because it is practical and durable in cutting for an extended period.

Diamonds excel in hardness and heat diffusion when used as a cutting tool. This is why diamonds may be used to cut nonferrous metal.

You may polish both materials to generate a razor-sharp cutting edge.


Because diamond is so intense, it may be utilized as an industrial cutting tool. In addition, a diamond is tough and resistant. As a result, diamond-encrusted equipment will outlive other machinery.

The machine will survive a long time if diamonds are utilized in the cutting tools. For example, a diamond saw device can withstand a lot of wear.

Tool Performance

Diamonds, due to their hardness, endurance, high melting point, heat resistance, and other characteristics, tend to boost the efficacy of an industrial tool when utilized.

They are not only created from carbon but also attractive when carved from their natural condition. They also have a more practical side that gets the job done.

However, they serve a far more functional role than merely being put in a ring to cement an engagement or in a bracelet or necklace to embellish beauty and then carefully stored away in a jewelry box or a safe.

Diamonds are not only beautiful in jewelry, but they are also significant in industrial settings.

So the last question is: Why are diamonds used as cutting tools, and why are diamonds used to cut other metals?

Simply – Because they are the most incredible option for getting the task done quickly and efficiently.

Related Read:

Final Thoughts

We tried to answer precisely the question: Why Is Diamond Not Used For The Machining Of Ferrous Material? As we said, our original answer to the question would be:

Although diamond tools are widely employed in cutting non-ferrous materials for high-quality mirror surfaces – you can’t use them to cut ferrous materials.

However, we did not perceive it as our only task. By answering the mentioned question, we raised new questions related to ferrous materials and metals and techniques along with methods for using diamonds for machining.

We started the article by explaining what ferrous metals are and ended it by explaining the use of diamonds as cutting tools.

We hope you had the opportunity to, in addition to gathering new information, learn many valuable things related to the topic that interested you in the first place.