What to Consider When Buying a Grinding Wheel
There are many companies offering grinding wheels for metalworking applications. However, it is crucial to buy the right one to avoid wasting money and time.
Many things should be considered when buying a grinding wheel, first of which is the material that you will use it on. This will dictate what abrasive is necessary for the wheel. If you work with steel, for instance, you should go for irconia alumina or aluminum oxide. For non-ferrous metals, non-metallics and cast iron, you should get silicon carbide.
Materials that are tough and brittle usually need a softer-grade wheel with a finer grit size. 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. On the other hand, a coarser grit and harder grade are best for softer materials that are easy to penetrate.
The amount of stock that should be removed is also a factor. Due to heavier cuts and stronger penetration, coarser grits will obviously take out stock at a higher speed. But a finer grit will be more effective for softer material.
In terms of bonds, wheels having vitrified bonds can cut more quickly. For removing tiny amounts of stock, shellac, resin or rubber bonds are advised.
Another thing that makes a difference when choosing a wheel bond is how fast the wheel turns in operation. Vitrified wheels often run under 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. High-speed grinding requirements can be met with specially designed wheels.
In any case, maximum operating speed limits indicated on the wheel or its blotter must not be exceeded.
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. Finer grits and harder grades are a must for smaller areas of grinding contact because of the greater unit pressure.
Next thing to check is grinding action severity. This is the pressure that holds the grinding wheel and the work piece together. There are abrasives made to endure extreme grinding conditions when working on steel and steel alloys.
Lastly, grinding machine horsepower needs to be factored into your choice of a grinding wheel. Harder grade wheels must generally be used on machines that have higher horsepower.A softer grade wheel must be used if wheel diameter is greater than horsepower. The reverse applies too.