Not all diamond blades are designed to cut the same materials. One important factor that affects a blade’s cutting performance and lifespan is diamond blade segment hardness.
Diamond blade segments are available with soft, medium, and hard metal bonds. Each type is designed to wear at a different rate, helping the blade expose fresh diamond particles as it cuts.
The basic rule is simple: hard, dense materials generally require a softer bond, while soft, abrasive materials generally require a harder bond. Choosing the correct bond helps improve cutting performance and can prevent premature blade wear.
Let’s look at how segment hardness works, why different types exist, and which applications are best suited to each bond.
What Is Diamond Blade Segment Hardness?
Diamond blade segment hardness refers to the hardness of the metal bond that holds the industrial diamond particles inside the blade’s cutting segments.
The diamonds do the grinding, while the metal bond holds them in place. As the blade cuts, the bond gradually wears away and exposes new diamond particles.
This process is important because the exposed diamonds eventually become dull or fracture. The bond must wear at the right rate to reveal fresh diamonds and maintain effective cutting action.
If the bond is too hard for the material, the blade may stop cutting efficiently. If the bond is too soft, the segments may wear away too quickly.
That’s why manufacturers produce different bond hardnesses for different cutting applications.
What Are the Three Types of Diamond Blade Segment Hardness?
The three common bond classifications are soft, medium, and hard. Each serves a different purpose.
1. Soft Bond Diamond Blades
Soft bond diamond blades are designed primarily for cutting hard, dense materials.
The softer metal bond wears away more readily. This helps expose fresh diamond particles when the existing diamonds become dull.
Soft bond blades are commonly used for:
- Hard, dense concrete
- Concrete containing hard aggregate
- Granite and certain hard natural stones
- Other dense materials when specified by the blade manufacturer
Why use a soft bond?
Hard materials can dull diamond particles without wearing away the metal bond quickly enough. A softer bond helps release worn diamonds and expose fresh cutting points.
This allows the blade to continue cutting effectively instead of becoming glazed.
2. Medium Bond Diamond Blades
Medium bond diamond blades offer a balance between bond wear and diamond exposure.
They are commonly used for general-purpose applications where the material does not require an especially soft or hard bond.
Medium bond blades may be suitable for:
- Certain cured concrete applications
- Concrete with moderate aggregate hardness
- General-purpose masonry cutting
- Mixed materials when the blade is specifically rated for those applications
Why use a medium bond?
A medium bond can provide a useful balance of cutting performance and blade life when working with materials that fall between very hard, dense surfaces and highly abrasive materials.
However, medium bond does not automatically mean every-material compatibility. The concrete mix, aggregate, equipment, and blade specifications still matter.
3. Hard Bond Diamond Blades
Hard bond diamond blades are designed primarily for softer, more abrasive materials.
The harder metal bond resists wear and holds the diamond particles in place for longer. This helps prevent the abrasive material from wearing away the segments too quickly.
Hard bond blades are commonly used for:
- Asphalt
- Green concrete, depending on the mix and application
- Soft, abrasive concrete
- Certain soft or abrasive masonry materials
Why use a hard bond?
Abrasive materials can wear away the metal bond rapidly. If the bond is too soft, it may release diamond particles before they have been used effectively.
A harder bond helps control this wear and can extend blade life in the right application. Asphalt-cutting blades may also include undercut protection to help protect the steel core from abrasive wear.
Why Are There Different Types of Diamond Blade Segment Hardness?
Different materials affect a diamond blade in different ways.
Some materials are extremely hard and dull the exposed diamond particles. Others contain abrasive particles that wear away the metal bond quickly.
A single bond formulation cannot deliver the best performance in every situation.
Manufacturers design different bond hardnesses to control how quickly the metal matrix wears and exposes new diamonds. Matching the bond to the material helps balance cutting speed, segment wear, and blade life.
For contractors, this can mean less time spent dealing with a blade that cuts slowly or wears out too quickly.
Diamond Blade Segment Hardness Chart
Use this chart as a general starting point when selecting a bond.
| Bond type | Typical applications | Main benefit |
|---|---|---|
| Soft bond | Hard, dense concrete and certain hard stones | Exposes fresh diamonds more readily |
| Medium bond | Suitable general-purpose concrete and masonry applications | Balances cutting action and wear |
| Hard bond | Asphalt and other soft, abrasive materials | Resists rapid bond wear |
These are general guidelines, not universal rules. Always check the manufacturer’s recommendations for the specific material, saw, and cutting conditions.
What Happens If You Use the Wrong Bond Hardness?
Choosing the wrong segment hardness can affect both cutting performance and blade life.
The Bond Is Too Hard
If the bond is too hard for the material, the diamonds may become dull without being released quickly enough.
This can cause glazing, where the blade’s cutting surface becomes polished and cuts slowly or struggles to cut.
A blade that is glazing may need to be dressed according to the manufacturer’s instructions, or replaced if it is damaged or worn beyond its service limits.
The Bond Is Too Soft
If the bond is too soft for an abrasive material, the segments can wear down too quickly.
The blade may lose its cutting life prematurely, increasing replacement costs and downtime.
Matching the bond to the material helps reduce both problems.
How Do You Choose the Right Diamond Blade Segment Hardness?
Before choosing a diamond blade, consider these factors:
- Material hardness: Determine whether you’re cutting hard, dense concrete or softer material.
- Material abrasiveness: Abrasive sand and aggregate can wear the bond quickly.
- Aggregate type: Concrete containing hard aggregate may require a different bond than concrete with softer aggregate.
- Cutting application: Asphalt, cured concrete, green concrete, and stone can require different blade specifications.
- Equipment: Make sure the blade is compatible with your saw, blade diameter, and operating speed.
- Manufacturer recommendations: Follow the blade manufacturer’s guidance for the material and cutting conditions.
If you’re unsure which bond is best, provide your blade supplier with the material you’re cutting, the type of saw you’re using, and whether you’re cutting wet or dry.
Final Answer: Which Diamond Blade Segment Hardness Should You Use?
Use a soft bond for hard, dense materials, a medium bond for suitable general-purpose applications, and a hard bond for soft, abrasive materials.
The right choice depends on more than material hardness alone. Abrasiveness, aggregate type, cutting conditions, and equipment all affect performance.
At Diamond King Tools, choosing the right blade for the job is an important part of getting dependable cutting performance and value from your tools.
Have questions about selecting a diamond blade for your next project? Reach out to Diamond King Tools for help finding the right blade for your application.
