What to Consider When Buying a Grinding Wheel
If you’re looking to buy a grinding wheel for metalwork, there are several vendors you can find nowadays. However, it is crucial to buy the right one to avoid wasting money and time.
Several considerations must be made before buying a grinding wheel, and the first is the material that you intend to use it on. This will dictate what abrasive is necessary for the wheel. For example, for steel alloys, zirconia alumina is a good choice. For non-ferrous metals, non-metallics and cast iron, you should get silicon carbide.
The harder and more brittle the material to be ground is, the softer the grade and the finer the grit size you’ll need. Since hard materials resist abrasion with great force, the grains tend to dull very quickly. The finer grit and softer grade formula works because the grains separate once they have dulled, and fresh, sharp cutters are exposed on the surface. Conversely, because softer and more ductile materials resist penetration less, a coarser grit and harder grade are more suitable to use.
Another important consideration is the amount of stock for removal. Stock is naturally removed faster with coarser grits because of the stronger penetration as well as the heavier cuts. But if the material is harder, a finer grit is better to use.
In terms of bonds, wheels having vitrified bonds can cut more quickly. If a small amount of stock should be removed, rubber, resin or shellac bonds should be used.
Another thing that makes a difference when choosing a wheel bond is how fast the wheel turns in operation. Vitrified wheels are typically operated at a maximum speed of 6,500 surface feet per minute. Higher speeds may cause the vitrified bond to break. Best for speeds of 6,500 and 9,500 surface feet per minute are organic bond wheels. High-speed grinding requirements can be met with specially designed wheels.
In any case, it is crucial not to go beyond exceed the indicated safe operating speed as shown on the wheel or its manual.
The next thing to consider is the area of the wheel-to-workpiece grinding contact. A wider area of contact calls for a softer grade and a with coarser grit. Because of the greater unit pressure, finer grits should be used for smaller areas of grinding contact.
Now it’s time to look into the grinding action’s severity. This is the pressure responsible for keeping the grinding wheel close to the workpiece. For extreme grinding, such as projects involving steel and steel alloys, special abrasives are made to withstand the pressure.
Lastly, grinding machine horsepower needs to be factored into your choice of a grinding wheel. Higher-horsepower machines often work with harder-grade wheels.If horsepower is less than wheel diameter, a softer grade wheel is advised. The reverse is also true.
The opposite is true as well.