Understanding the Different Types of Carbide in Cutting Tools

When it comes to machining, choosing the right cutting tool can make a big difference in your results—and at the heart of many of these tools is carbide.

But not all carbide is the same. There are different types and grades, each designed for specific applications.

If you’re a decision-maker in the machining industry, understanding the types of carbide in cutting tools can help you make smarter purchasing decisions, reduce tool wear, and improve part quality.

In this guide, we’ll break down the different types of carbide used in cutting tools, explain what makes them different, and offer tips to help you choose the right one for your job.

What Is Carbide and Why It’s Used in Cutting Tools

Carbide is a hard, dense material made by combining tungsten and carbon atoms into a compound called tungsten carbide (WC).

This material is then mixed with a binder—usually cobalt—and pressed into shape to form a solid, high-strength cutting tool.

Carbide is widely used in cutting tools because of:

Extreme hardness: It stays sharp longer.
Résistance à l'usure: It can cut even tough metals like stainless steel and titanium.
Heat resistance: It works well at high speeds without losing its edge.

That’s why carbide tools are often the top choice in industries like automobile, aérospatial, pétrole et gaz, fabrication de moules, and general manufacturing.

Cemented Carbide: The Industry Standard

The most common type of carbide used in cutting tools is cemented carbide, also known as hardmetal.

This is made by mixing tungsten carbide particles with a metal binder, typically cobalt, and sintering them at high temperatures.

Depending on how it’s made, cemented carbide can be optimized for different applications:

More cobalt = more dureté (but slightly less wear resistance)
Less cobalt = harder tool (but may chip under heavy loads)

This balance between dureté and toughness is key when selecting a grade.

Cemented carbide is used in:

Fraises
Inserts
Drills
Turning tools

C-Grades and ISO Grades: Understanding Classification

Carbide tools are often labeled using either C-grades (in the U.S.) ou ISO grades (internationally). These grading systems help users match a tool to the right application.

1). Common C-Grades in the U.S.:

Grade	Application
C1–C2	Cast iron, non-ferrous metals
C3–C4	Usinage à usage général
C5–C6	Steel cutting
C7–C8	High wear resistance, tough applications

2). Common ISO Grades:

Qualité ISO	Application
P	Steel
K	Cast iron
M	Acier inoxydable
N	Non-ferrous metals (aluminum, copper)
S	High-temperature alloys (Inconel, etc.)
H	Hardened steels

Each grade is designed to handle a specific combination of wear, toughness, and temperature resistance.

Micrograin and Ultrafine Carbide: High Precision, High Strength

Not all carbide particles are the same size. Some are extremely fine—these are called micrograin or ultrafine carbide. These small grains result in a smoother, stronger material.

1). Benefits of micrograin carbide:

Excellent edge sharpness
Higher toughness compared to regular fine-grain carbide
Ideal for small tools like micro end mills, dental burs, or precision drills

2). Typical uses:

Electronics machining
Medical tool manufacturing
High-precision mold making

If your work involves tight tolerances or tiny features, micrograin carbide tools may be your best bet.

Coated vs. Uncoated Carbide Tools

While the core material of a tool matters, coatings also play a big role in tool performance.

Carbide tools can be either uncoated or coated with materials like TiAlN, TiCN, or diamond-like carbon (DLC).

Fonctionnalité	Coated Carbide	Uncoated Carbide
Résistance à l'usure	Haut	Modéré
Résistance à la chaleur	Excellent	Modéré
Finition de surface	Amélioré	Depends on the application
Coût	Plus élevé à l'avance	Inférieur

Use coated carbide when machining tough or abrasive materials. Choose uncoated tools for softer metals, plastics, or low-speed operations.

Recycled Carbide: Good for the Planet and Your Budget

Another type gaining attention is recycled carbide. Old or worn-out carbide tools can be collected, ground down, and reused to make new tools.

Some suppliers offer high-quality recycled carbide that performs nearly as well as virgin material.

Benefits of recycled carbide:

Lower cost
Reduces environmental impact
Helps companies meet sustainability goals

Make sure to verify the quality and origin of recycled tools. A reputable supplier will clearly label and test these tools.

Selecting the Right Carbide for Your Application

Here’s a quick guide to help match carbide types with your application:

Material Being Cut	Recommended Carbide Type	Preferred Coating
Steel	C5 / ISO P	TiAlN
Stainless Steel	C6 / ISO M	TiCN
Aluminum	C2 / ISO N	DLC or Uncoated
Fonte	C1–C2 / ISO K	Étain
Inconel or Titanium Alloys	ISO S	TiAlN or AlTiN
Acier trempé	ISO H	CVD diamond or special coatings

Key Takeaways for Decision-Makers

If you’re responsible for selecting or approving cutting tools in your shop or company, here’s what to remember:

Not all carbide is the same—different grades and grain sizes suit different jobs.
Coatings enhance performance, especially in high-speed or difficult materials.
Micrograin carbide tools offer higher precision and toughness for small parts.
Recycled carbide is eco-friendly and cost-effective—if sourced correctly.
Always consider both tool material and coatings when choosing for specific applications.