Grinding discs

It’s crucial to choose the best grinding wheel for your project, but with so many options available for grinding discs and wheels, it can be difficult to make a decision. In order to help you make the best decision possible, we have created this comprehensive summary.

What is a grinding wheel?

A grinding wheel’s abrasive grains cut into the material being ground, chipping away the undesired surface material.

The cutting edges of the abrasive grains get flattened and increasingly dull during grinding. In addition, the increased friction leads to a rise in temperature, which breaks down the abrasive grain and exposes new cutting edges or starts to break down the binding bridges that hold the abrasive grains together.

In typical vitrified grinding, a dressing tool is used to dress the wheel. Grinding wheels can have a wide variety of various grinding characteristics by modifying the abrasive’s qualities, the type of bond, and the wheel’s design.

What Grit Size Do I Need?

Coarse Grit Size

A coarse grit can be utilised when the job does not require the neatness of the surface finish. Additionally, faster stock removal results from more coarse grit, making it better suited for large regions of contact than fine grained abrasives.

Additionally, they are the greatest choice for ductile, stringy, and soft materials like soft steel and aluminium.

Fine Grit Size

When the finish is crucial to the project’s success, fine grits are used. Additionally, select a finer grit when the project calls for closer, more accurate work across a smaller area of contact. The finer gritted abrasive is best suited for hard and potentially brittle materials including glass, tool steel, and cemented carbide.

How to Choose the Right Grinding Wheel Grade?

The grade represents the bond’s relative capacity to hold abrasive grains in a wheel.

Soft Grades

• For tough substances like hard tool steels and carbides
• For quick stock clearance
• For large contact areas

Hard Grades:

• For delicate materials
• Longer wheel life 
• For small or narrow contact regions.

What Material Will You Be Grinding?

The choice of abrasive, grit size, and grade is influenced by the type of material.

• For grinding high tensile materials like steel and ferritic cast irons, alumina type abrasives are best. On tougher steels and applications requiring large contact arcs, the more friable varieties of alumina are preferable.
• The most effective way to grind or cut non-metallic and low tensile strength materials is with silicon carbide abrasive. The degree of penetration that the abrasive can achieve depends on how hard the material is.
• Because of this, grinding hard materials calls for wheels with a finer grit size, whereas soft materials work best with wheels of a medium to coarse grit size. The grade needs to be changed to meet the material’s hardness for the best operation.

As a general rule, softer wheel grades are needed for tougher materials.

Stock/material to be removed

• The need for coarse grit wheels, typically 12 to 24 mesh, arises from high stock removal rates, such as in fettling processes.
• Finer grit sizes are necessary for final workpiece geometry restrictions and fine finishing. Final surface polish is frequently achieved via “spark out,” which involves stopping all infeed and letting the wheel grind until the majority of the sparks stop.