K390 and S110V Discussion Thread

[Holland]

Thanks for testing the mule Jim! love all your work

[DJ]

Thanks for testing the mule Jim! love all your work

Me Too ............Iam here always Lurking

[senorsquare]

That's saying a mouthful. Imagine 5 years ago thinking about a release in this steel. Heck, S110V for that matter, but especially K390, a non stainless super steel in the A11 ( mod) class. Sal has made a career of raising the bar higher and higher. The very low profit margin mule team program uses production time that could be assigned to far more lucrative knives with higher margins. Not only do we get mules we get K294.

It still amazes me when I think about it. Sal is as big a knife knut/steel junky as any of us. That is apparent.

Joe

I'm still kind of tripping out on the fact that I just got an S110v and a K390 blade for $220 total. That's just nuts.

[DJ]

:cool:

[Holland]

I'm still kind of tripping out on the fact that I just got an S110v and a K390 blade for $220 total. That's just nuts.

Indeed it is! :D Thank you Sal and your wonderful company :)

[md8232]

Thinking about doing one after I get it back, sending it out next week.

Getting a mod?

[Ankerson]

That's saying a mouthful. Imagine 5 years ago thinking about a release in this steel. Heck, S110V for that matter, but especially K390, a non stainless super steel in the A11 ( mod) class. Sal has made a career of raising the bar higher and higher. The very low profit margin mule team program uses production time that could be assigned to far more lucrative knives with higher margins. Not only do we get mules we get K294.

It still amazes me when I think about it. Sal is as big a knife knut/steel junky as any of us. That is apparent.

Joe

Joe,

Yes, Sal really pushes the envelope as far as steels goes and I think K390 was a great choice in an A11 class steel for the Mule Team.

Jim

[chuck_roxas45]

Joe,

Yes, Sal really pushes the envelope as far as steels goes and I think K390 was a great choice in an A11 class steel for the Mule Team.

Jim

These are great times for a steel head on a budget. :D

[Ankerson]

These are great times for a steel head with a budget. :D

Yep, getting this kind of performance for $70, only have to add scales and maybe a sheath, but still, extreme performance at a reasonable price.

[The Mastiff]

Yep, getting this kind of performance for $70, only have to add scales and maybe a sheath, but still, extreme performance at a reasonable price.

It does give me pause. It's not one I would have asked for due to the difficulties involved no matter how much I secretly wished it to come to pass. It's truly an astounding steel and it shows not only Sal's willingness to give the people here a knife in a blade steel that is an AFI only steel if I've ever seen one.

It also shows that Sal has a great deal of confidence in the cutlers, grinders putting the edge on, heck, everybody involved in the whole process. Even the heat treater he uses.

Another first for Sal and Spyderco though Sal has so many of those I doubt he keeps track any more. It makes one wonder what's next, or even what else will be possible in the next 5 years.

I still won't be asking. I'll leave that to others as I would feel bad after all he's done for us/me and the knife industry in general. I'll only express desire for these over the top projects if asked. That's not from any lack of interest though, but respect. Not at least until I feel I can pay him back for some of the favors he's done for us knife knut/steel junkys. Besides, he's at the near peak of performance as things currently stand, as far as cutting goes. Higher alloyed, higher carbide steels may not actually give better results due to lack of edge strength causing thicker edges and angles to be needed. I'm thinking about that slab of 15V I still have, as well as some others like S125V, the Rex steels, MPL-1/Supracore , etc.

Niche steels like W2, or O-7 ( Cliff had a god idea in that one) , S1, and a few others that can do amazing things though not quite lead the pack in wear resistance. 4V is one I really want to try. I should get along with it from the things I've heard about it.

Sal, It's going to be tough to out do MT 17P. I'm not going to doubt you but even if you stopped the mule team You have already done much, much more for us than anybody else has even considered doing. A big thanks!

Joe

[Ankerson]

Just finished reprofiling and sharpening the S110V forum knife with the Congress Moldmaster 320 grit (reprofiling) and 400 grit (finished edge) to 15 DPS, didn't take long at all, around 15 mins or so and screaming sharp.

Somewhat easier than K390 from my impressions from dealing with both within a few days of each other.

[JNewell]

Just finished reprofiling and sharpening the S110V forum knife with the Congress Moldmaster 320 grit (reprofiling) and 400 grit (finished edge) to 15 DPS, didn't take long at all, around 15 mins or so and screaming sharp.

Somewhat easier than K390 from my impressions from dealing with both within a few days of each other.

Freehand or EP or other?

[Ankerson]

Freehand or EP or other?

Edge Pro. :)

[chuck_roxas45]

Just finished reprofiling and sharpening the S110V forum knife with the Congress Moldmaster 320 grit (reprofiling) and 400 grit (finished edge) to 15 DPS, didn't take long at all, around 15 mins or so and screaming sharp.

Somewhat easier than K390 from my impressions from dealing with both within a few days of each other.

You are an Edge Pro monster Jim. :D

[Ankerson]

You are an Edge Pro monster Jim. :D

Gotten used to it over the years. :D

[DJ]

This is about steel and sharpening so Iam gonna ask here ...............Ive bought a sharpmaker , just havent gotten it yet and I want to order some moldmaster triangle rods for it.
What size do I get ?? 1/2 in. ?? or 1/4 in. ??

[Cliff Stamp]

This is from the Bohler website:

Jim,

To clarify, you don't listen to Roman's commentary on steels even though he uses peer reviewed and published literature to support his arguments - and your defense of that position is that Roman is just shilling to support selling his knives.

However you readily take the marketing data as unbiased fact from the company which is selling the steel?

I thought K390 wasn't a knife steel.

It isn't for the reasons noted, these are metallurgical facts. Come on Philo, the same man who took out the legendary Tank Murdock can't possibly fall for such basic marketing. When Jimmy Beekman tried to leverage you against Jack Wilson for your come back you saw through that immediately.

The secondary hardening cycle doesn't improve the performance unless you actually want high tempering resistance (the tools are exposed to very high heat in use, ~500 C).

Now will marketing oppose this - of course it will, that is what marketing does.

One of the strongest examples of this is shown in the history of ATS-34 which has a very strong secondary hardening response (intentionally it was designed as a stainless which could take high heat). It was used for knives and the secondary hardening response was utilized. A number of makers, manufacturers and users all defended this as being optimal.

However the metallurgical data was clear that the edge stability, corrosion resistance, and toughness were all seriously degraded. Finally one maker, Ernest Mayer of Black Cloud Knives went public and challenged one of the bigger names in the business, Paul Bos, and said that the low temper cycle was superior.

Paul Bos and other makers and manufacturers (and users) attempted to argue with anecdotal data. However as more people became aware of the issues (which are *really* basic metallurgy) in a short period of time even Paul Bos reversed and used the low temper ATS-34 cycle. There was simply too much data to keep ignoring it especially after Hitachi released a large document comparing the two cycles for ATS-34.

Now simply because something isn't a knife steel doesn't mean you can't use it in knives, and doesn't mean it is the worst thing you could use. If for example you wanted knives for a commercial kitchen you could use 440C, which is a ball bearing stainless steel. It would be better than a lot of choices, however it is directly worse than steels actually designed for that exact purpose such as 12C27M.

As for rope cutting, you simply can not be even close to precise with rope cutting on a scale due to the limitations of measurement and the non-linear behavior of blunting. The math on this is quite clear, as even a few basics :

-the most you can get with careful measurement is about +/- lbs

This is extremely insensitive, to be precise when you make a cut with a knife on a scale and the knife has a very thin cross section you can cut it with a 2" draw with about 10 lbs. However this 10 lbs doesn't measure the sharpness, the bulk of it is a wedging force which doesn't change in the cutting, the actual part which measures the sharpness is only about 1 lbs.

-this means that your sharpness measurement error is actually +/- 100%.

This is compounded when you take the knives to low sharpness because the response is non linear.

Initially you can see changes quickly, however late in the cutting it changes very slow and you literally have to keep doubling cuts to see differences. This is again basic physics and it means that late in the cutting you can do hundreds of cuts and not be able to see a significant difference.

The critical part is that it means that one knife could be easily twice as good as another on the extended rope cutting can you would not be able to see it.

As an example, here is some actual data for a run with a D2 knife cutting 3/8" hemp on a 2" draw (this is number of cuts and pounds on the scale):


2, 8.0
6, 8.5
14, 7.5
30, 8.5
62, 9.5
126, 11.5
254, 9.5
510, 11.0
1022, 13.0

(at 1022 cuts it was 13 lbs).

Now if this knife had the performance increased by 100% the numbers would not significantly change because the spread in them was about a lbs. This means you could not tell those knives apart by doing such work. This is also why the measurements go up/down it is random.

This, among other reasons is why I moved away from using cutting hemp as a test of sharpness more than a decade ago. I used it early on as it was popular, however it simply doesn't have the necessary precision to do even gross comparisons as you can't even significantly see a difference of +/- 100 %.

If you claim such differences to be significant you have just fallen for one of the oldest experimental traps which is expectation/confirmation bias.

[Donut]

If you claim such differences to be significant you have just fallen for one of the oldest experimental traps which is expectation/confirmation bias.

The cheese in that trap looked so tasty, too.

[Cliff Stamp]

The cheese in that trap looked so tasty, too.

That is exactly why so much care has to be taken in experimentation, because one of our most powerful drives is expectation bias. Few things make someone happier than being proven right, and there are few things more aggravating then your own work proving you wrong. Both get stronger the more vocal you have been on the issue.

This is why so much time is devoted to scientific methodology because of the ease of which bias will influence results even when there is no conscious desire to do so. Hence why double blinds and similar methods are so useful as they minimize bias. They are difficult, demanding and much more time involved - but they are necessary.

Of course even they don't prevent bias totally because even the selections of the methods used and the participants, nature of the trails, if you are actually going to reveal the results etc. all have an influence. This is why secondary verification is critical.

It is always trivial to know who is seeking information and who isn't because you can see a clear pattern of behavior.

Elliot of Ferrum Forge, Mike Gavac, Kevin Cashen, (and many more) makers all clearly embrace metallurgy and questions/concerns from users and critical analysis. Spyderco has always had a history of the same which is one of the reasons I respect the company.

The bottom line is very simple, there is a reason various steels exist, they all are the best choice possible for something. All that you need to do is clearly ensure that something is what you want when you are picking a steel because they are also the worst choice possible for something as well.

[Blerv]

Cliff, what is your current edge setup for your custom RJ Martin in CPM-110v? How has this served you?

Thanks :)