Diamond crystals are the hardest substance known to man (see chart above). They are generally 1.7 times harder than their nearest competitor, CBN (Cubic Boron Nitride). Even so, CBN is far superior to diamond wheels when it comes to grinding steel. This is because of the affinity of Iron (in the steel) to react with Carbon (in the diamond) to form Iron carbides in the metals surface, which results in very high wheel wear. CBN does not have this problem.
However, when it comes to grinding non-ferrous materials, like high-tech ceramics, there is nothing better than diamond wheels. Now Meister
Abrasives'expanded range of vitrified diamond wheel choices gives users more options than ever
for the best possible finishes, removal rates, and machine cycles.