Understanding Grit Size, Concentration and Bond in Diamond & CBN Wheels

Introduction

Selecting the right Diamond or CBN grinding wheel involves much more than choosing the correct wheel shape or abrasive type. Three critical factors determine the performance of a grinding wheel:

• Grit Size

• Abrasive Concentration

• Bond Type

These elements directly influence surface finish, stock removal rate, wheel life, grinding forces, and overall productivity.

Many grinding challenges such as poor finish, excessive wheel wear, overheating, or low material removal rates can often be traced back to an incorrect combination of grit, concentration, and bond.

This guide explains how these parameters work together and how to select the right combination for your grinding application.

Why Wheel Specification Matters

Diamond and CBN wheels are engineered systems designed to achieve specific grinding objectives.

A properly selected wheel can help manufacturers:

• Improve productivity

• Increase wheel life

• Achieve superior surface finish

• Reduce grinding costs

• Improve dimensional accuracy

• Minimize machine downtime

Understanding the relationship between grit size, concentration, and bond is the first step toward optimizing grinding performance.

What is Grit Size?

Grit size refers to the size of the abrasive particles used in a grinding wheel.

Simply put:

Larger Grit Number = Finer Abrasive

Smaller Grit Number = Coarser Abrasive

Examples:

Grit Size	Classification
D46	Very Fine
D64	Fine
D91	Medium
D126	Coarse
D151	Extra Coarse

The choice of grit size affects both material removal and surface finish.

Coarse Grit Wheels

Coarse grit wheels contain larger abrasive particles.

Characteristics

• Higher stock removal

• Faster grinding cycles

• More aggressive cutting action

• Rougher surface finish

Typical Applications

• Rough Grinding

• Heavy Material Removal

• Tool Manufacturing

• Production Grinding

Common Grit Sizes:

• D126

• D151

• D181

Fine Grit Wheels

Fine grit wheels contain smaller abrasive particles.

Characteristics

• Smoother surface finish

• Higher dimensional accuracy

• Lower stock removal rate

• Better edge quality

Typical Applications

• Tool Sharpening

• Finishing Operations

• Precision Grinding

• Medical Components

Common Grit Sizes:

• D46

• D64

• D76

How Grit Size Affects Grinding Performance

Coarse Grit

Advantages:

✓ Faster stock removal

✓ Lower grinding temperatures

✓ Reduced cycle time

Limitations:

✗ Rougher surface finish

✗ Lower edge quality

Fine Grit

Advantages:

✓ Excellent finish quality

✓ Better dimensional control

✓ Sharper cutting edges

Limitations:

✗ Lower material removal rate

✗ Longer grinding cycles

The ideal grit size depends on whether productivity or surface finish is the primary objective.

What is Abrasive Concentration?

Concentration refers to the amount of Diamond or CBN abrasive contained within the wheel bond structure.

It determines how many cutting points are available during grinding.

Higher concentration means more abrasive particles are present within a given wheel volume.

Common Concentration Levels

Concentration	Typical Use
C50	Light Grinding
C75	General Purpose
C100	Standard Industry Use
C125	High Precision
C150+	Long Wheel Life Applications

Low Concentration Wheels

Lower concentration wheels contain fewer abrasive particles.

Benefits

• Freer cutting action

• Lower grinding forces

• Reduced heat generation

Applications

• Carbide Tool Grinding

• Sharpening Operations

• Light Grinding Tasks

High Concentration Wheels

Higher concentration wheels contain more abrasive particles.

Benefits

• Longer wheel life

• Improved profile retention

• Better dimensional stability

Applications

• Production Grinding

• CNC Tool Manufacturing

• High Precision Grinding

Choosing the Right Concentration

If the goal is aggressive cutting and low grinding pressure, lower concentration may be preferred.

If the goal is longer wheel life and profile stability, higher concentration generally provides better results.

The correct concentration depends on machine power, material type, coolant conditions, and production requirements.

How Grit Size, Concentration and Bond Work Together

A grinding wheel performs best when all three parameters are properly matched.

Example 1: Carbide End Mill Manufacturing

Recommended Specification:

• Diamond Abrasive

• D64 Fine Grit

• C100 Concentration

• Hybrid Bond

Result:

• Excellent edge quality

• High productivity

• Long wheel life

Example 2: HSS Tool Sharpening

Recommended Specification:

• CBN Abrasive

• D91 Medium Grit

• C75 Concentration

• Resin Bond

Result:

• Superior finish

• Cool grinding action

• Accurate cutting edges

Example 3: Production Gear Grinding

Recommended Specification:

• CBN Abrasive

• D126 Grit

• C125 Concentration

• Vitrified Bond

Result:

• High material removal

• Excellent profile retention

• Consistent production quality

Common Mistakes When Selecting a Grinding Wheel

Many users focus only on abrasive type and overlook wheel specification.

Common mistakes include:

• Using overly fine grit for rough grinding

• Selecting low concentration for high-volume production

• Choosing the wrong bond system

• Prioritizing wheel cost over performance

Proper wheel specification often delivers greater savings through improved productivity and wheel life.

Why Choose Eurogrind Superabrasives?

, Eurogrind Superabrasives has been helping manufacturers optimize grinding performance through customized Diamond and CBN wheel solutions.

Our expertise includes:

• Diamond Grinding Wheels

• CBN Grinding Wheels

• Hybrid Bond Wheels

• Resin Bond Wheels

• Vitrified Bond Wheels

• Metal Bond Wheels

• Electroplated Wheels

• Diamond Honing Stones

• PCD & PCBN Tooling Solutions

Every wheel is engineered according to application requirements, ensuring maximum efficiency and reliability.

Conclusion

The performance of a Diamond or CBN grinding wheel depends on far more than the abrasive itself.

Grit size determines the balance between stock removal and surface finish.

Concentration influences wheel life, cutting efficiency, and profile retention.

Bond type controls wheel behavior, heat resistance, and overall grinding performance.

Understanding these three key factors enables manufacturers to select the right grinding wheel for every application, resulting in improved productivity, better surface quality, longer wheel life, and lower manufacturing costs.