I’ve seen a lot of confusion lately about when to choose cbn vs diamond for precision cutting or grinding - especially with ceramics, carbides, and ferrous alloys. In many applications, the two perform very differently, and selecting the wrong abrasive can waste tools and damage material.
For anyone comparing performance, bond types, heat behavior, or ideal applications, this detailed breakdown on cbn vs diamond is one of the clearest resources I’ve come across. It covers why diamond excels on non-ferrous ultra-hard materials, while CBN is the safer choice for steels due to thermal stability.
If you’re trying to decide which abrasive suits your process, it’s worth a read.
Diamond excels on brittle or non-ferrous materials (ceramics, glass, carbide) because of its extreme hardness and clean cutting action. It shouldn’t be used on steels due to chemical reactivity with iron at high temperatures. CBN is the correct choice for hardened steels, cast irons, and other ferrous alloys since it remains thermally stable and chemically inert in those conditions.
In short:
Correct summary. One key distinction is thermal chemistry: diamond degrades on ferrous alloys at elevated temperatures, while CBN remains stable and maintains cutting efficiency. For brittle, non-ferrous ultra-hard materials, diamond still provides the fastest, cleanest cut. Choosing based on material response to heat usually yields the best results.