steelcity16 wrote: ↑Sun May 12, 2019 7:59 pm
Larrin wrote: ↑Sun May 12, 2019 11:29 am
thewoodpecker wrote: ↑Sat May 11, 2019 10:25 am
I am curious. Why does CPM S35VN have such low toughness if the carbide content is lower than CPM-154/Elmax/M390/etc.?
Vanax and S35VN have similar carbide/nitride volume and look similar. M390 appears to outperform relative to those. Why CPM-154 does so much better I don’t know. Hoping to do some more samples sometime in the future.
I am surprised to hear that about Vanax. I feel like Xplorer has said he regards it much higher it the toughness category in his use on the custom knives he makes. Hopefully he will chime in with his opinion on the accuracy of that chart relative to his extensive experience making blades.
Frankly, I'm finding I'd prefer to stay out of these conversations. My goal is to find real answers with regard to actual knife performance results, and these conversations don't necessarily lead to such conclusions for a wide variety of reasons. There are so many major factors that affect the actual results you will see in the knife you hold in your hand that the steel itself is not as important as these threads would lead one to believe. This is more true when talking about toughness than any other steel attribute. Toughness of an actual knife is far more effected by heat treat and geometry than edge retention or corrosion resistance for instance. You might be surprised to learn that while I might argue for or against one steel or another within a given narrow context...at the end of the day I will also say "meh...(shrug shoulders)...it doesn't really matter...there are a ton of great steels and I can make a knife that 99% of people would consider a superior performing blade with any of them". That's not me being arrogant...that's the reality of steel quality today and the enormous affects of geometry and heat treat when you understand how to achieve the necessary balance required for the intended application.
To answer your questions about what I have been saying about Vanax toughness...Vanax is 25% tougher than Elmax according to the data I have received directly from a metallurgist and project engineer that I have been working with directly at Uddeholm. All of the knife specific test I have performed have confirmed this to be true. It's important to keep all of these comments and results in their proper context. For instance...Vanax is unique and extremely special steel only if corrosion resistance is a high priority. If the intended application requires extreme corrosion resistance, LC200N (Z-FiNit) is the toughest, S110V is the hardest (due to the low edge retention I do not include H1..toughest..in these comparisons). Vanax provides a balance of properties that is unique in that it is harder and will hold an edge longer than LC200N and it is tougher than S110V and much, much easier to sharpen. But, take away the context that corrosion resistance is highly important and there's nothing all that special about the remaining properties. The big benefit I see in Vanax is the unique
balance. It basically makes a blade that stays sharp longer than S30V/S35VN, with more toughness, easier sharpening, and it will never corrode. Perfect for a low/no maintenance EDC and also perfect for fillet and fishing knives of all sorts.
Regarding toughness again, the other PM grade stainless steels (like S35VN, S30V, M390, N690) fall just below Elmax but are so close that the toughness differences in actual knives are irrelevant. However, each of those others listed can achieve better hardness than Elmax at the compared toughness levels (this is one of the things that makes these conversations confusing and easily misleading). AEB-L is not a PM grade stainless which is why I hadn't compared it to the others in the past, but make no mistake...AEB-L is amazing steel and makes an insanely tough (the toughest) stainless blade. Why CPM154 shows up on that chart with such high toughness numbers is a mystery to everyone apparently. I've never seen any other information that would back that up. I make knives in CPM154 and I love that steel...it has a great balance of properties overall. Crucible shows CPM154 toughness as equal to S30V
http://www.crucible.com/PDFs%5CDataShee ... v12010.pdf . My personal test results with actual blades have lead me to conclude that CPM154 is roughly equal in toughness to S30V / S35VN but edge holding is not as good. When I see information that is that far outside of all other available data I consider it questionable at best. I'd like to know how that result was derived, but it wouldn't change the results that I actually see in knives either way.
I would encourage anyone interested in "toughness" to think in depth about how toughness, hardness, carbide structure, material thickness and bevel angle all interact together. It is the balance of these properties that really provides the results and dialing in that mixture correctly is how you actually make a knife perform in the manner that you desire.
Best regards,
Chad
:spyder: Spyderco fan and collector since 1991. :spyder:
Father of 2, nature explorer, custom knife maker.
@ckc_knifemaker on Instagram.