I Tested the Edge Retention of 48 Steels

[tonijedi]

Nice job Larrin.

Your findings and ours are very similar. We've got Maximet in stock if you need any.

sal

It would be nice to test H1 as well...

[Deadboxhero]

It would relate to animal hide/fur

Phil Wilson has an article on Seamount Knifeworks you can read about how rope may compare to animal hide.

http://www.seamountknifeworks.com/js/we ... e_test.pdf


CATRA has a correlation with rope cut testing but is more wearing on the edge due to the 5% silica abrasive in the card stock.

The testing is done to see how the STEEL stacks to other STEELS in controlled edge slicing to see what steels have more wear resistance than others.

Real world depends more on how the end user sharpened it and how they are using it and for what. Followed by a big list of other things. Geometry, HT, etc

Using various available cuts of meat, it would be interesting if Larrin could tell us how skin/meat/tendons compare to CATRA card stock.

I will never be attacked with a CATRA machine or CATRA card stock. How could these results be better related to the cutting of real world materials(human and animal flesh)? The tests are excellent, and I am in no way trying to diminish them, but for the guy/gal taking down an elk/deer what can we definitively say?

How can we approximate the number of cuts through 3/8 leather jacket? A down Winter coat? 3 T-shirts?

Just throwing this out there for thoughts.

[zuludelta]

Wow, just did a quick scan of the article an hour ago and I'm blown away by the amount of work, money, and detail that went into it.

Thanks for doing this, Larrin, it's an incredible resource. More than anything, I think it provides us with what I think is the best publicly-available empirical baseline reference for how a given knife steel will perform in terms of edge retention relative to another knife steel, all other factors being held constant. And now that we have that baseline, we can start making better ballpark assumptions about how edge angle, steel toughness, and Rockwell hardness will affect a knife's overall performance.

And rather than contradicting some of the real-world observations and "conventional wisdom" we have about knife steels, I think the article helps explain why they are so. For instance, I always thought it a little strange that so many people (including Pete from the Cedric & Ada YouTube channel) found plain edge LC200N out-cutting plain edge VG-10 when the "on paper" chemistry did not seem to allow for it. But since LC200N's superior toughness allows it to better support steeper sharpening angles, I can see how it can outperform VG-10 in a rope cutting test despite having a lower "potential edge retention". And I think this also helps explain Spyderco's decision to stick with VG-10 & CPM-S30V as its baseline steels for many of its most popular models at a time when it seemed like every other premium maker of note was shifting to D2 (or 14C28N) & CPM-S35VN.

Coupled with your recent-ish article on knife steels and corrosion resistance, I think I am significantly better informed about which knife steels will work best in my specific context than ever before, and that is very, very valuable. At the very least, being equipped with this information means less time and money wasted trying out knives just for their material differences, allowing me to focus on things like ergonomics and handling when considering a potential knife purchase.

[Larrin]

Nice job Larrin.

Your findings and ours are very similar. We've got Maximet in stock if you need any.

sal

Thanks, Sal. I agree our findings line up pretty well. I will let you know if we need any Maxamet. I think we have some now to test. But I can never have too much steel. :)

[blues]

Larrin, Shawn...hats off to you both. Awesome job and very educational. Corroborated a few of my own biases as well as providing a few surprises.

We owe you a great debt.

[sal]

Hi Larrin,

I think we're sitting on some H1 well. We use it for our Autos.

One of the dowsides of rope cutting is that you are cutting on something like a cutting board which also has an effect.

Hey Zuludelta,

We've been CATRA testing steels for 20+ years and we find that Real World Testing is also very important as there are sometimes differences that are not easily explained.

Then add serrations to the mix and edge retention is further complicated.

sal

[Larrin]

Hi Larrin,

I think we're sitting on some H1 well. We use it for our Autos.

One of the dowsides of rope cutting is that you are cutting on something like a cutting board which also has an effect.

Hey Zuludelta,

We've been CATRA testing steels for 20+ years and we find that Real World Testing is also very important as there are sometimes differences that are not easily explained.

Then add serrations to the mix and edge retention is further complicated.

sal

H1 would be cool to get. My plan is to use rope in the CATRA machine. I know it fits but I don’t know for sure if it’s possible yet.

[senorsquare]

... I did not expect M4 to be below S30V in anything. M4 seems to be the recipient of excellent marketing, and S30V, not so much...

Looks like M4 in this test has fairly equivalent wear resistance with S30V with both at approximately 61 Rc, and M4 having significantly greater toughness. The HRC database thread shows that Spyderco tends to run their M4 around 64 Rc and it would be interesting to see results for M4 tested at 64-65 Rc.

[Ruudr]

What an awesome article to read. Thanks for the huge amount of work you’ve put into it.

[zuludelta]

Hey Zuludelta,

We've been CATRA testing steels for 20+ years and we find that Real World Testing is also very important as there are sometimes differences that are not easily explained.

Then add serrations to the mix and edge retention is further complicated.

sal

Yup, serrations are a definite "x-factor" in my experience as far as real world cutting performance goes. My Combo Edge Delica 4 and Endura 4 seemingly exceed the potential predicted by their chemistry with regards to working edge retention.

[Pancake]

I didn't read the whole article, but I will for sure, but thank you for your hard work! We, as a knife community are very fortunate that we have people like Larrin and BBB in our ranks.

As for results, yes, the mighty boring S30V still left a lot of steels behind. And 204p did only marginally better. S30V, after nearly 20 years, still rocks.

[Phil Wilson]

HI Larrin, do you ever sleep? Incredible body of work including getting a very complicated machine working and gather all the samples to test. You have a good partner with BBB. A few sort of surprises but in general they fall right where you would expect. CPM S30V and CPM S90V are right in there with what I have experienced with my testing. A lot of grades are more alike than different and this shows up here. They can shift around bit based on heat treat and sharpening and you have shown that with your other work on toughness for example. If you look you can see some "categories" and groups begin to stand out. My experience is that rope cutting can show you a lot and in general it does allow for predictions on how a knife will perform in the field. CATRA takes out a lot of the variables and your work here will become the standard reference for all us knife nuts. You are into it now. As they say make one knife use it and end up making a thousand. We can't help ourselves, Phil

[Larrin]

HI Larrin, do you ever sleep? Incredible body of work including getting a very complicated machine working and gather all the samples to test. You have a good partner with BBB. A few sort of surprises but in general they fall right where you would expect. CPM S30V and CPM S90V are right in there with what I have experienced with my testing. A lot of grades are more alike than different and this shows up here. They can shift around bit based on heat treat and sharpening and you have shown that with your other work on toughness for example. If you look you can see some "categories" and groups begin to stand out. My experience is that rope cutting can show you a lot and in general it does allow for predictions on how a knife will perform in the field. CATRA takes out a lot of the variables and your work here will become the standard reference for all us knife nuts. You are into it now. As they say make one knife use it and end up making a thousand. We can't help ourselves, Phil

Thanks Phil, I agree that it makes more sense to think in categories a lot of times. Arguing over which steel did marginally better than another doesn’t mean much. I see a lot of internet discussions debating steels that are in the performance “category” when moving to a different category would provide much more difference. It’s like wine connoisseurs seeing things that may or may not be there.

[blues]

Larrin, REX 45, did I miss any mention of it? I tried to be thorough but I'm not as young as I used to be...(Thanks again for awesome work. You and Shawn should never have to buy another drink.)

[Deadboxhero]

Larrin, REX 45, did I miss any mention of it? I tried to be thorough but I'm not as young as I used to be...(Thanks again for awesome work. You and Shawn should never have to buy another drink.)

Lawdog :D, still need to add Maxamet and Rex 45
Maybe Sal is interested in sending some. :)

Maybe in the .125" thickness with a nice surface finish too :D


There are some other ones to add that I'll need to heat treat, surface finish, hardness test, grind and sharpen.

M398, Vancron, A6, CTS-XHP, and 19c27.


I think it will be fun to keep adding more and more over time if cost, time and peoples interest allows for it.

[wrdwrght]

I shudder to think what it took for you and Shawn to obtain these data, but I’m glad you did.

And I’m especially grateful that you insisted on coupling edge-retention to toughness. Their combined effect and their more imponderable effects on each other are what make knives so intriguing to me.

Thanks, Larrin. I’ll be buying your book.

[Larrin]

Larrin, REX 45, did I miss any mention of it? I tried to be thorough but I'm not as young as I used to be...(Thanks again for awesome work. You and Shawn should never have to buy another drink.)

Hopefully we can get some Rex 45. I will have to ask Sal as none of it is available to buy in individual bars. Identical steels are more common in Europe so it may be possible to import a different but identical steel. Rex 45 is in between M2 and M4 when at identical hardness.

[blues]

Thanks, gents!

Lawdog, out. :cool:

[fixall]

I can’t wait to get home from work so I can dive into this!

Thanks!!!

P.S.
You’re gaining a Patreon follower when I get home because it is long overdue.

[marty_bill_]

Thank you for your time and effort. This is awesome! Great information !