Stuck In the Metals With You

Cushing H.

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For those of you who (likely most...) dont get the reference in the title, I refer to the following music video...

Yesterday my son was asking if I could make a knife for a friend of his who likes to cook. So, as part of that discussion, I was trying to talk about different types of steels this friend might want. I first went to Larrins data on toughness, then decided that a correctly used kitchen knife should not be abused so much that toughness is a real issue ... and so went to Larrins data on edge retention ( https://knifesteelnerds.com/2020/05/01/testing-the-edge-retention-of-48-knife-steels/ ). If you look at his chart on edge rention versus hardness ... this is wonderful data ... but it is enough to make your eyes cross. Add to that issues like how well it grinds, how straightforward the HT is, and how likely it is to warp .....

Well, you get the idea ..... it is easy to get lost in the metals.

The recent (current) thread on "best steels for hunting knives" kind of reinforces the potential for confusion .... lots of different ideas and perspectives out there. None wrong ... but each coming from a different set of experiences and perspectives. Horsewright has hundreds and hundreds of working knives out there made of A2, whereas rodriguez7 will swear by Z-wear, 4V or 3V .... all of which are on very different places on Larrins TCC chart (well, Z-wear isnt on there, but I will assume it lies somewhere between 4V and Z-Max....). It is enough to make you scream....

So ... unless one truly is a Knife Steel Nerd (and just want to try a steel for the sake of it, or are really interested in small differences in performance) .... what is one to do???

So ... this is what I am thinking. I have tried enough different steels to see/feel that they definitely work differently. O1 is kind of ... meh. AEBL is a PITA - hard to grind cleanly, and I still (for whatever reason) get pull-outs on the edge when I try to take it to a small TBE (I know this is not supposed to be the case ... but for me it definitely is an issue). A2 is reasonable to work with ... still a little fussy getting a clean grind, but not too bad. CPM-154 is very reasonable to grind (maybe because of the PM process and the microstructure it produces?), and 26C3 ("Spicy White") is wonderful to work ... at least pre-HT.

If you look at Larrins edge retention chart, the steels seem to fall into three basic categories. The first, centered around A2 and 1095 (mostly carbon or "simpler" steels) have lower edge retention and simpler heat treats (and I think tend to be used at lower HRC). The second group, centered roughly around S35VN and CPM-M4) have higher edge retention, tend to to be more complex (mostly "stainless"), have more complex HT, and (again from what I think I have seen) people tend to push to higher HRC. The last group, starting at ZDP-189 going up to Z-Max, have high edge retention, again more complex HT, and from what I have heard are an absolute bear to grind after HT (Z-Max even before), and basically forget about getting a mirror finish on them....

But, within each group (roughly), just how different are the steels in performance? Just how different in performance is A2 from 1095 and the other steels in this group (granted that there is some significant variaion in corrosion resistance in this group)??

How different, really, is CPM-154 from S35VN and S45VN? (previous discussion have indicated the differences between 35VN and 45VN are "small"). Z-Max seems to be in a world all its own .... but how different, really, are say S90V versus ZDP-189?

I am beginning to come to the conclusion that the way out of this is to, within each group, choose one (at most two) steels that work well for you (either by way of workability, cost, corrosion resistance (say A2 versus 1095).

For me (pretty exclusively kitchen knives) I am thinking A2 for non-stainless (maybe 26C3 if I want higher hardness). CPM-154 (maybe S35VN after I check workability) for stainless kitchen knives. If I really want to try to experience higher HRC, I might give Z-Max a try (but the task of grinding it might put me off....)

A knife meant for heavy duty field dressing (as rodriguez7 describes) is way, way out of my experience ... so I wont venture any thought on that one.

What do you all think ... is this approach a way out of the confusion ..... or am I just forever stuck in the metals??
 
You should assume that Z-Wear is identical to CPM CruWear since the two steels are identical.
 
You should assume that Z-Wear is identical to CPM CruWear since the two steels are identical.
thanks Larrin. btw - just looked at that old thread that Stacy referenced. Fun WIP to look through, and a beautiful blade!
 
You are a bit late to the party. Nick Wheeler and Lorien made a series of tutorial posts titled "Wheelers Steel * Stuck in the Metal with You" about ten years ago.
Thanks, Stacy. I was trying to figure out how to point this out without sounding like I was scolding....
 
(philosophical drivel)
I want to understand the details of every steel in such a way that I can transform a customer's needs into the perfect choice of steel.
I realistically don't think this will ever happen. My reasoning:
  • Stories about the almost mythical Don Fogg steel (W-2?) and how it doesn't behave like others of the same name. Could be a different blend of chemistry within the tolerances of that steel type
  • New "super steels" coming out with some regularity. Even the mighty Larrin hasn't tested all the steels. Spicy white is relatively new, even though it's not a high alloy steel.
  • What counts as "use" vs "abuse": My mom hacked into a beef bone with a chef's knife. And I cried. I think the knife did, too.
Given that mankind has used steel knives for at least 30 years and we can't agree on the ideal qualities, I suspect that we never will.
I want to believe in perfection as opposed to compromise. But materials engineers have convinced me that perfection may not be attainable.

A competitive market exists to satisfy the needs of many. If one steel is definitively better, we will expect to see it win the market share, like VHS (trolling) or AC power (trolling).
An informed and practiced knifemaker can justify why they choose a specific steel, and a customer can choose to agree or not. And the customer is always right (trolling).
 
Thanks, Stacy. I was trying to figure out how to point this out without sounding like I was scolding....
Well ... in my defense, I was not on the forum 10 years ago... and the duplicate is the title (though theirs, given the authors, is much, much appropriate and humorous). The intent of the subject At hand, though, is really pretty different. So, the point I was trying to make, and the request for discussion, still stands....
 
How do you decide? Pick one or two, and make a bunch of blades. Make them thin, hard, and see how they hold up. Make more, and push your geometry and hardness until they break. Then you know what your equipment can create.
 
Consider revisiting your AEBL challenges. I don’t use it a lot but I find it to have very good workability all around. I think it’s a pleasure to use compared to more difficult high alloy steels.
 
Consider revisiting your AEBL challenges. I don’t use it a lot but I find it to have very good workability all around. I think it’s a pleasure to use compared to more difficult high alloy steels.
I do have two more blanks in aebl that I need to finish ... so I will get a chance to revisit the aebl challenges. If I run into what I did before (3 times) I will definitely post (not sure how soon I will be able to get to those particular blanks though... :-(
 
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