Guide to Grinding Wheels: Material, Bond, Grain size, Grade, Specification, Types

Hi everyone! Today’s discussion revolves around grinding wheels, where we’ll dissect their materials, bonds, grain sizes, grades, structures, types, defects, and unravel the secrets of reading their specifications.

The grinding process incorporates the utilization of the grinding wheel, playing a pivotal role in the broader spectrum of manufacturing processes.

You’ve highlighted an essential aspect of grinding wheels – their application across various types of grinding machines, including surface grinding machines, tool and cutter grinding machines, centerless grinding machines, and cylindrical grinding machines. This versatility underscores the importance of grinding wheels in machining processes.

The goal of exploring this subject is to furnish you with the expertise needed to attain impeccable surface finishes, uphold precision in shape and dimensions, hone cutting tool edges, refine cast and welded surfaces, and accomplish a myriad of other tasks with exceptional quality standards.

So, let’s begin by understanding the grinding process, which is facilitated by the grinding wheel.

Grinding Process

The process involves metal cutting, known as grinding, to eliminate excess material and attain the desired surface finish.

In grinding, metal is removed in form of chip.
Grinding Process
Grinding Process


Grinding Wheel Definition

Utilized primarily in grinding operations, it functions as a cutting tool to execute cutting tasks effectively.

Grinding Wheel Material

It is made up of two components which are given below
1. Abrasive
2. Bond/Binders


Tough and hard granular materials, known as abrasive particles, are utilized to eliminate the protrusions on workpieces during the grinding process. The selection of these particles is based on the material being ground.

Grinding wheel abrasives

It is of two types which is  given below
•Natural Abrasive
•Artificial Abrasive

Natural Abrasive

Naturally occurring abrasives are referred to as natural abrasives.

Eg corundum, emery, diamond, etc.

Artificial Abrasive

Artificial abrasives are those that are created through manufacturing rather than occurring naturally.

The different types of artificial abrasive are as follows
•Aluminium Oxide
•Silicon Carbide
•Artificial Diamond

Aluminium Oxide

Known for their hardness, toughness, and sharp edges, the particles of this abrasive are ideal for grinding carbon steel, mild steel, wrought iron, and die steel. As a result, aluminum oxide abrasive type grinding wheels are extensively employed in industries and factories.

It is denoted by A.

Silicon Carbide

The brittleness of silicon carbide molecules makes it suitable for grinding low tensile strength metals like cast iron, bronze, copper, ceramic, etc., using silicon carbide grinding wheels. Hence, aluminum oxide abrasive type grinding wheels are widely preferred in industries and factories.

It is denoted by C.

Artificial Diamond

The diamond made artificially is know as artificial diamond.
It is hard as natural diamond.
It is denoted by D.


Bonding involves the strong adherence of materials. It encompasses the use of different abrasive grains like silicate, shellac, rubber, and metal.

Types of bond in grinding wheel

Bonding materials used for making the wheel is given below
•Vitrified Bond
•Silicate Bond
•Shellac bond
•Resin or Resinoid Bond
•Rubber Bond
•Metal Bond
•Oxychloride Bond
•Reinforced Resin Bond

Vitrified Bond

Comprised mainly of feldspar, it is blended with additional refractory substances to establish a durable bond. Immune to water, acids, oils, and standard temperature ranges, it is symbolized by the letter V.

Silicate Bond

In this bond, silicate is used to bind the abrasive particles.
It is denoted by letter S.

Shellac bond

This bonding method involves mixing abrasive particles with shellac, followed by heating.

It is denoted by letter E.

Resin or Resinoid Bond

It finds its primary application in table grinding, swing grinding, snagging grinding, cam grinding, and various other grinding operations.

It is denoted by letter B.

Rubber Bond

After mixing the abrasive particles with rubber and sulfur, the mixture is shaped and heated to form the desired grinding wheel.

These are used for good surface finishing. It is denoted by letter B.

Metal Bond

It finds application in grinding very hard metals such as tungsten carbide, among others.

It is denoted by letter M.

Oxychloride Bond

It is utilized without coolant, particularly in industries such as file or razor blade manufacturing.

Reinforced Resin Bond

This bond type is predominantly utilized in manufacturing industries and is represented by the designation BF.

Grain or Grit Size of Grinding Wheel

The dimension of the abrasive particle is referred to as grain size or grit size.

According to IS standards, grain sizes are divided into four groups.

(i) Coarse size
(ii) Medium size
(iii) Fine size
 (iv) Very fine size

Coarse Size

Grain size number from 10 to 24.

Medium Size

Grain size number from 30 to 60.

Fine Size

Grain size number from 80 to 190

Very Fine Size

Grain size number from 200 to 600.

Grade of Grinding Wheel

Grading is done from A to Z in grinding wheel which is given bellow
•Soft Grade
•Medium Grade
•Hard Grade

Soft Grade

When selecting a grinding wheel with a soft grade, you can choose from grades A to H of the wheel.

Soft grade grinding wheels are denoted by letters ranging from A to H.

Medium Grade

Medium grade grinding wheels are denoted by letters ranging from I to P.

Medium grade grinding wheels are denoted by letters ranging from I to P.

Hard Grade

If using Hard grade grinding wheel then choose from Q to Z grades of the wheel.
That means hard grade grinding wheel denoted by the letter from  Q, R, S, T, U …… to Z.

Structure of Grinding Wheel

The structure of the grinding wheel refers to the entity of the grinding wheel.
Here are two types of structure as
•Open Structure
•Close Structure

Open Structure

The structure that incorporates a significant amount of binder to provide separation between the particles is referred to as an open structure.

Close Structure

The structure without separation between the particles is termed as a close structure, where the binder used is in lesser quantity compared to the open structure.

Specification of Grinding Wheel 

To specify the grinding wheel, it’s essential to understand the following terms that have been previously discussed. This allows us to comprehend how to read the specifications of a grinding wheel.

• Grinding Wheel Material
• Grinding wheel bonding material
• Grain or Grit Size of Grinding Wheel
• Grade of Grinding Wheel
• Structure of Grinding Wheel
Grinding Wheel Specification
Grinding Wheel Specification
Now we specified grinding wheel through figure one by one
(1) In a figure shown dimension of grinding wheel  ∅105×1.2×16mm
105 – Diameter of grinding wheel
1.2 – Thickness of grinding wheel
16 – size of arbor hole
(2) In a figure of grinding wheel shown
A 46 N BF
A – It is denoted the type of abrasive where “A” means aluminium oxide.
46 – It is denoted the grain size of grinding wheel where “46” represent medium size.
N – It is defined grade of grinding wheel where “N” represent medium grade.
BF – It is defined bonding materials of grinding wheel where “BF” represent reinforced resin bond.

Types of grinding wheel

Grinding wheels are manufactured in various shapes and configurations, tailored for specific operations and compatible with different types of machines.

Typically, various types of grinding wheels are available for different applications, including:

•Straight Wheel
•Tapered Wheel
•Cylindrical Wheel
•Straight Cup Wheel
•Herring cup wheel
•Dish Wheel
•Saucer Wheel
•Diamond Wheel

Straight Wheel

It is used for cylindrical, centreless and surface grinding operation.

Tapered Wheel

It is used for snagging grinding, gear tooth, etc.

Cylindrical Wheel

It is used for grinding the plain or curved surface.

Straight Cup Wheel

It is used for off hand grinding.

Herring cup wheel

It is used for sharpening the milling cutter.

Dish Wheel

It is used for grinding the slots and devices.

Saucer Wheel

It is used for grind milling cutters and twist drill.

Diamond Wheel

It is used for grinding extremely hard materials.

Grinding Processes

Before grinding, the following operations are typically performed on the grinding wheel:

• Dressing of the grinding wheel
• Truing of the grinding wheel
• Balancing of the grinding wheel
• Mounting of the wheel on machine

Defects in Grinding Wheel

The defects in the grinding wheel are as follows


The accumulation of ground chips between the abrasive particles of the grinding wheel is referred to as loading.

Loading is caused due to
(i) Putting workpiece by the wheel.
 (ii) Taking cuts that are too deep.
(iii) Grinding of soft material.
 (iv) By using a wheel of too hard bond and running it too slowly.


It refers to the condition where the face or cutting edge of the tool takes on a glass-like appearance.
The glazing is happening due to following reasons
(i) Using hard wheel on hard metals.
 (ii) More speed of revolution or wheel.
 (iii) Less feed of the job.
You’ve covered a lot of ground discussing grinding wheels and related terminology. It seems like you’ve provided a comprehensive overview of the topic!

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