Hey everybody!
I've been thinking about the more "exotic" steels lately and wondering what everyone else thought about them. From reading articles on Knife Steel Nerds ( https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by-a-metallurgist-toughness-edge-retention-and-corrosion-resistance/), it seems the big trade-off being reckoned with is between edge retention and toughness, with stainless being an additional factor.
From the charts there, it seems carbon steel is the go-to where toughness is concerned, but even there, I have questions. 1095 is rated half as tough as 1084 with the same edge retention, which surprises me since (at least in my mind) they are very similar metallurgically, and I would think 1095 would have better edge retention from the increased carbides. Does that mean 1095 is just...worse than 1084?
And then we get to the high-alloy and stainless sections, which look like they really shine edge-retention-wise. I don't see many bladesmiths using steels in these categories and I'd like to know why not. Is it because they're difficult/not suited to forging? I'm also curious if the increased wear resistance makes grinding/finishing exceedingly difficult, and that's why I've never seen a knife made of Rex 121, for example.
Looking at the data, it makes sense that a camp knife/bowie/fighter would be made from carbon steel. Would lower-impact knives such as skinning and in the kitchen be better suited by steels in the high-alloy and stainless categories? I'm interested in making the best kitchen knives I can, so I'm thinking about getting some 10V or something to play around with, if it really is supposed to be so superior to the carbon steels I've been working with.
Please let me know your thoughts, especially if you've branched out in your steel selection,
-Ethan
I have a few thoughts. As far as forging I think High alloy steels and most stainless are definitely not suited for it but, it is possible you don't see it very often though. A few more considerations are cost, machinability ,need for cryo and the ability for a customer to sharpen. Having said that also take a look at Magnacut. To cheat on the finishing and cost I've made San mai with Apex ultra and Z-wear. At least doing San mai I can use a 4×1.5 inch piece for a 9 inch Chef knife and have less supersteel to finish. With both those when sand the sandpaper wants to skate all over. Even Aeb-l (nice mix of edge retention and cost) San mai at 62 rc becomes hard to finish.
Edit: sand should be sanding. And Aeb-l (nice mix of edge retention toughness and cost). also you can mess with the heat treat recipe for Aeb-l.
Edit button still spinning
I would say several things come into play, High alloy steels are more expensive, harder and more expensive to heat treat, harder to forge with high chromium content making a lot of chromium oxide and decarb. All of that without a truly significant gain to the user. most SS alloys knives are made with stock removal. And carbon steel and low alloy are much easier to sharpen by the end user out in the field.
Data is just that data, basing your understanding of performance on numbers is fine, but you need to account for ALL of the variables. I like larin (Knife steel nerds) and his work is interesting, but he tends to present his data and the conclusions he gets from it in absolutes. This is fine in and of its self, but if other data is added to the mix those conclusions can be no longer valid.
As an example of 1095 vs 1084, heat treat can make huge differences in the performance of 1095 and there are a number of methods to get the most out of it, the slightly lower Manganese make is more prone to hamon and harder to get to through harden and higher carbon makes thing require a lot more control. the two are very different for all they look similar on paper.
The gains in performance even from the very best of steels wail real and small in the scope of things, even the gains from real perfect heat treat over a just OK heat treat are relatively small. for me it is about repeatability balancing the geometry heat treat and steel choice, and much of those choices come down to what equipment and I have available.
I forge my stainless knives because i get 2-3 times the yield from the bar, the performance from empirical testing is to my standards and i have worked out best practices for each alloy I work with. Larins latest work is showing the possibility of a marked improvement in the performance of stainless when forged.. I don't know about that my goal has always been to put it back in the same state as I started.
MP
I was hoping MP would hop in. 🙂
Some old posts he contributed to are what I referenced when I tried out stainless (mostly AEB-L for what I tried), and I just did not care for it at all. More expensive in general, harder to forge, tighter temperature ranges, took longer and required more investment to heat treat, and then I saw how much more work forge welding is for it. And AEB-L is supposed to be one of the easier stainless steels to forge with. Definitely not for me while I'm still gathering shop tools and learning.
It can be done obviously. I was largely inspired by Devin Thomas (Larrin Thomas' / Knifesteelnerds dad) at the time. Goodness does he have some gorgeous stainless damascus. But I determined it was too much of an investment for me for a few points on a graph.
I think trying to maximize your knives for their purpose is an excellent endeavor and well worth it if you have the patience, but I've yet to see a knife be like some holy grail steel over a good carbon steel one. The point differences on KSN's tests just don't translate as substantially to practical use as we might hope, though you can still feel some difference. If I'm buying stainless though, it's mostly just because I don't want to worry about keeping it clean/dry as much. Which is also why my edc pocket knife is a lc200n salt series from spyderco. Not buying it for the edge retention or durability, buying stainless for it to be stainless. So while Larrin is making strides in changing people's minds on stainless, I think that rust resistance is still the main market. And the small performance increase you might be able to squeeze out eventually just won't be worth the additional costs put into it to most people.
So if you do go for it, expect a tighter market for the output and a decent amount of frustration. But also know I'd be very interested to see your success, especially with the experiments going on right now with stainless steels.
