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. But you need to pick the right one so you don’t end up wasting cash and time.
There are different things to look into when shopping for a grinding wheel, and the first is what you plan to use it on. This determines the type of abrasive you will need. For instance, aluminum oxide is recommended for steels and steel alloys. If you plan to use your grinder for non-metallics, cast iron and non-ferrous metals, experts advise silicon carbide abrasive.
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. With a finer grit and softer grade, the grains can break away as they turn dull, while fresh and sharp cutting points come to the surface. Conversely, because softer and more ductile materials resist penetration less, a coarser grit and harder grade are more suitable to use.
It’s also important to determine how much stock has to be removed. Due to heavier cuts and stronger penetration, coarser grits will obviously take out stock at a higher speed. 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 consideration that should be made is the speed of the wheel during 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. When speeds reach 6,500 to 9,500 surface feet per minute, organic bond wheels are recommended. When higher speeds are required, specially designed wheels are often necessary.
In any case, operating speed should not be higher than the maximum recommended in the manual.
Next, check the area of grinding contact between the wheel and the material to be ground. Broader areas of contact mean a coarser grit and softer grade should be used. Finer grits and harder grades are a must for smaller areas of grinding contact because of the greater unit pressure.
Now it’s time to look into the grinding action’s severity. This pressure is what keeps the grinding wheel and the workpiece close together. Certain abrasives are designed for severe grinding conditions, such as when grinding steel and steel alloys.
Lastly, grinding machine horsepower needs to be factored into your choice of a grinding wheel. Harder-grade wheels normally run with greater horsepower.In cases where horsepower is less than wheel diameter, experts recommend a wheel of a softer grade. The reverse applies too.