Definitely 154CM and the reasoning behind the 57-59 hardness is because any harder and the knife could possible snap if you were trying to pry something open. While we don't recommend or warranty and knife that was used for prying, Mr Emerson states that a broken knife is just garbage while a dull knife is still a knife....or something close along those lines. I agree with that logic completely. These knives were made to be sharpened in the field and if had to, run across the pavement or rock to get a sharper edge.
I did not know you harden only to 57-59 HRC because your 154CM performs like other 154CM I have used closer to 59-61!!!
I think you will find that if you move from 154CM to CPM-154, you will see a big improvement in both edge retention and toughness (but especially toughness). It would also allow hardening CPM-154 to higher levels but still have toughness which exceeds that of 154CM at current hardness. I find the uniform carbide distribution of CPM-154 makes it easier to sharpen also. As a plus for you, I've read CPM-154 is much easier to machine.
I agree with Mr. Emerson's logic completely, and that is the core reason I am asking about CPM-154. Given your emphasis on the importance of toughness, I think that makes you more likely than others to appreciate just how much CPM-154 improves over 154CM (and most other stainless steels for that matter). The real-world benefit is significant. Knives in CPM-154 around 60-61 HRC I've done things to that would outright break most other blades (including those in 154CM).
If you can get 154CM at 57-59 HRC to perform as well as it does, you're clearly competent with the heat treatment process of 154 and I can only imagine what you could do with CPM-154. You're company is loyal to Crucible and American workers, and feel strongly that 154 is a spectacular steel. And I agree and think that mindset is awesome. Based on your experience and your mission, it seems almost a natural evolutionary step for you go to CPM-154 as you could keep 154 while taking things up a few notches, stay with Crucible, keep something that is easier to sharpen, go to higher hardness levels while actually gaining substantially in toughness, and be at a
huuuuuuuge performance advantage over any maker using 154CM, which is a 'by default' performance/selling advantage.
I have both praise and criticism for almost every production maker. But the bottom line is that I believe you respond to your customers, you build great knives, your edge geometries are fantastic, and you clearly spend a lot of time in the planning and R&D stages, all of which I admire. If I didn't, I would not post this to begin with.
If you go to CPM-154, that admiration will improve greatly, and I will purchase many more of your knives. Given your appreciation of the importance of toughness, if there is any maker I could see going to CPM-154, it's Emerson...