I remember the good ole days when selecting a blade for cutting stone was fairly simple. There were very little choices — you had a blade for granite and one for marble. Today, with the development of diamond blades, the proper selection of a blade for granite, marble, limestone, engineered stone, porcelain, glass, etc., can be confusing.
How does a fabricator select the proper blade for cutting? The first step is to understand how a diamond blade cuts.
Diamonds are the hardest mineral known to man. They also do not have the ability to cut. That's right, diamonds do not cut; they work by abrasion. As the diamond blade moves its way through the stone or masonry, it grinds the material away. As the diamond grinds, it will wear and eventually fracture.
The diamonds are bonded to the blade with several types of bonding agents. The way the diamond is bonded will determine how the diamond will wear and the type of stone it will cut. It's beyond the scope of this article to discuss the bonding types; however, you should be aware that there are hard bonds and soft bonds. The bonding agent is typically metal of varying hardness and mixtures. In addition to holding the diamond in place, the bond also controls how the diamond will wear as well as how slow or fast it will cut and perform overall. If you look closely at a diamond blade you will see a comet trailing the diamond. This tail is the bonding material wearing. As the bonding wears, so will the diamond. The rate of wear is a direct relationship to how the diamond is bonded.
In general, a hard bond is used for soft stones and masonry, and a soft bond is used for hard stones and masonry. At first this doesn't make sense until you realize that a soft bond is needed to expose more diamond to cut harder stones, whereas a hard bond doesn't need to wear away as fast with a soft stone.