CBN is the next hardest material to diamond, yet in hand and high speed operations, it cuts even faster. (In high speed grinding operations, it is actually harder than diamonds - just FYI). CBN products are often more expensive than diamond in specific applications. It is particularly effective for hard knife steels over 60 HRC (Rockwell hardness), although it is quite respectable with softer steels too. It does a wonderful job on leather, balsa, paper and felt - tested in both freehand and on precision guided devices too. I have personally tested these compounds on multiple Japanese knives, scissors, etc and gotten excellent feedback on the edges (otherwise known as repeat customers). It is friable, like polycrystaline diamond too and gives prolonged cutting action. Dr. Matt Recommended!