Grinding discs are also a type of abrasive. In such tool, the abrasive works like the teeth in a saw. But what is different is that in saws, usually the teeth are one only one side. But in case of grinding discs, the abrasive grains are spread all over. When these grains move hard against the materials, it cuts the excessive parts. Through this, the extra materials are removed, and the surface is smoothened. These discs are also available in different grades. The soft grades are usually to use against hard tool steels or carbides where the surface area is large. On the other hand, the hard grades are to be used for soft materials and places where there is low surface area. The soft grades can do its work faster than the slower ones. But the soft grade abrasives usually last for lesser time because of their use. While choosing, you should understand the requirement and then get the right ones.