samuraistuart

What I wanted to mention Stuart and forgot is when I say my D2 filet knife is flexible, it is 59 RC+ hard flexible, but that is the triple temper and I even looked up my old notebook from Hinderliter about temper before cryo with D2 and it's on some HT instructions. One thing about D2, no overheating, put it into the oven when preheats are reached. If oven overshoots, take them out until proper temp is hit. Most D2 failure is overheat and tempers not right.
My O1 blades come out where I want them too with flexibility. I sold an O1 filet knife for a $300 charter, because the skipper cleaned over 40 fish without once stopping to sharpen it and that is a lot of bones to cut through. Edge geometry is also in play here. I sharpen by hand, always have and always will. He filleted at least 40 more fish before touching up the edge with a small diamond I gave him.

Hey Stuart I hear you, but I did have O1 crack on me when I went straight from quench to cryo which is why I do the pre-temper. The guys at Hinderliter were the ones that told me always to temper D2 before cryo or I might have my blade crack a year later. I'm going back to the 90s here when I basically did two steels, O1 and D2. At my last job Hinderliter was a huge resource for me and a small HT company around the corner from my job. I forged some too.

D2 is a tricky steel, and I used to not cryo it at all, same for O1 until I read some scientific studies that dry ice is very useful and I spoke to my metallurgy teacher. I have an A.S. in engineering and many other classes besides including metallurgy, but not as many classes in heat treating. My O1 and D2 come out where I want them though and that's all that counts. Pardon my ramblings yesterday, I'm in a lot of pain and am taking morphine and so I tend to ramble.