K390 Edge Retention Test- Diamond VS Aluminum Oxide

There is a common theory that when sharpening high vanadium steels, diamond are a must.
With out diamond or CBN the user will experience "Carbide tear out"

In this video I take k390... a 9%+ vanadium steel... and do a edge retention test.
Once with diamond stones
Once with aluminum oxide stones

I also go to war with a burr...yea

https://docs.google.com/document/d/1IA8Bup15LyghOsmEbEBEaUUlvImh094tVQTSXjNm1-E/edit?usp=drivesdk