CPM S30V and hardning

[gull wing]

Do you think the hardning process at Golden is much different than at Tiawan?
I ask because I recently got a Para 2(my first Golden knife in several years) and it seems to hold that scary sharp edge longer than my Sages. Now this is not scientific, just an observation.
Of course the blade thicknesses are different, Para being thicker.
What do you think?

[Cliff Stamp]

There would be expected to be significant differences among blades of the same steel for many different reasons, first among them is that the composition of the steel itself will vary from melt to melt. Then each heat treatment also has tolerances (in the mill) and each heat treatment in the knife also has tolerances. These variances are easily large enough that if you took a bunch of S30V blades and a bunch of S90V blades from the same manufacturer you would find some S30V blades which held up better slicing cardboard than some of the S90V blades for example.

[bh49]

These variances are easily large enough that if you took a bunch of S30V blades and a bunch of S90V blades from the same manufacturer you would find some S30V blades which held up better slicing cardboard than some of the S90V blades for example.

A little scary is not? To buy S90V blade and get performance of S30V. Opposite scenario sounds much better. :D

[Cliff Stamp]

A little scary is not? To buy S90V blade and get performance of S30V.

It is the reality of random variances. Note as well that I am talking about the blade performance, not the observed performance which is very different. The observed performance is subject to much wider tolerances, you can easily thus see a 420HC blade outperform a S90V blade simply because the cardboard you cut with one is much more demanding than the cardboard you cut with another. Even on very similar looking material, 1/8" single ridged, you can easily see a 10X different in effect on the edge (amount of material cut to achieve a set dulling) simply by cutting one box with one knife and a different box up with another. This factor of 10X is larger than the difference between all cutlery steels even from the minimum to the maximum in terms of hardness/wear and the effect it has on edges. It is normally why that before you make a conclusion on a knife you either have to use it a *lot* or take specific steps (random sampling, etc.) to ensure you are not simply seeing random influence.

[chuck_roxas45]

A little scary is not? To buy S90V blade and get performance of S30V. Opposite scenario sounds much better. :D

Scary indeed!!!

[Blerv]

It's a David vs Goliath comparison without the religious stuff.

Let's randomly assign a range in edge retention from 1 to 10. A 1-3 in S90v is beat by a 7-10 in S30v. Without getting into probability (because I'm an idiot) any roll of the dice where they are comparable the S90v wins; any dice roll where it out ranks s30v numerically it wins even bigger.

Almost anything is possible. Since guarantees are rare you have to reduce variables and stack odds in your favor. In this case paying more and tossing extra dice.

[chuck_roxas45]

It's a David vs Goliath comparison without the religious stuff.

Let's say a range in edge retention from 1 to 10. A 1-3 in S90v is beat by a 7-10 in S30v. Without getting into probability (because I'm an idiot) any roll of the dice where they are comparable the S90v wins; any dice roll where it out ranks s30v numerically it wins even bigger.

Almost anything is possible. Since you can't predict the details of results you have to reduce variables and stack odds in your favor. In this case paying more and tossing extra dice.

Hehehehe. I didn't understand a thing, sorry. :D

My deficiency entirely.

[Blerv]

Hmm, sorry.

Not all motorcycle crashes are fatal. Less crashes driving semi trucks are though. If you were asked to pick one to hit something we all would have the same answer.

CPM-S90v is a semi truck.

[Cliff Stamp]

If I give you a dice which has numbers from 1-10 and my dice has numbers from 1-5, on average you will roll higher numbers, but on some rolls I will still win. The same thing happens with steels. This is why there is so much variation in what is reported as people will use a knife for a very small amount of work and make large conclusions about the steel. All they are seeing in the majority of cases is simply a lucky/unlucky dice.

[Blerv]

Cliff's level 10 Wizard analogy just destroyed my Level 3 Orc Pawn analogy.

Thanks Cliff :) .

[gull wing]

Yah!

[MachSchnell]

Do you think the hardning process at Golden is much different than at Tiawan?
I ask because I recently got a Para 2(my first Golden knife in several years) and it seems to hold that scary sharp edge longer than my Sages. Now this is not scientific, just an observation.
Of course the blade thicknesses are different, Para being thicker.
What do you think?

I notice the same... My S30V Para hold's a great edge and doesn't chip easily or much at all, but the same can't be said about my S30V Manix and BM 940 Osborne (both are fairly easy to get tiny chips on the edge, but stay plenty sharp).

[Fancier]

What I take from this thread is that we should buy many knives, and keep the ones we like and sell the rest to compensate for the manufacturing variability.

[Blerv]

Well, assuming the average person or even those not participating in cut tests can even tell a difference besides the placebo effect.

Edge geometry per knife is going to make a bigger difference than the nuances of a specific heat-treat. At least if it's within an acceptable range that is (ie not messed up). A Para2, Manix2, and BM 940 don't have similar grinds, blade shapes or even thicknesses so if you ask 10 people you won't get consistent opinions.

Personally, I LOVE the placebo. It's one of the most consistent things you can buy. :)


Note: I think Gull Wing (or Cliff) can probably can tell the difference in those two knives even with the slightly different blade dimensions. I sure couldn't though. Potentially the shorter blade with more acute grind is putting more wear on it's 2.5ish inches of cutting length than the Para2. Perhaps it's the heat treat. No clue.

[Cliff Stamp]

Well, assuming the average person or even those not participating in cut tests can even tell a difference besides the placebo effect.

If you don't take specific steps to remove it that is all you are going to see, it is an insanely strong effect because we are inherently biased and irrational. The more you know, the more you are very likely to force what you observe to match what you know even subconsciously. Hence the need for things like double-blind procedures.

Curiously, we only tend to be unbiased and rational when we don't care about something at all as then logic is the fall back as there is no emotional involvement in the outcome. This is why if you are going to do an uncontrolled test, make sure the guy doing it doesn't care at all what happens and ideally doesn't know anything about the steel, knife, etc. . Or again, use procedures which are intended to remove bias.

[dbcad]

Good discussion :) Especially appreciate the academic bent.

From what I've read and tried to interpert the final properties of the blade material are the result of a tolerance stack of all stages of blade production, from melt to final finish. This makes a great deal of sense because no dynamic non-linear system is capable of 100% efficiency. There will always be losses and variances along the way.

I would think this is the same for every blade material :) I can say that IMO S30V is a very nice blade material. The Swick and PPT are 2 of my sharpest and toughest blades. We're all a little edge and steel nutty here and as a result discern differences in material properties most would miss.

Thanks for the discussion :) Quite enlightening :)

[Wolverine666]

I thought (and I could be wrong) that the blades for the Sage Series were made in Golden and the knives were assembled as a whole in Taichung. So if this were true then the hardening process would pretty much be the same I would think.

[The Mastiff]

Darn Cliff. There you go again! .

You know we want to hear what we want to hear. You know better! Tell us what we want to hear so we all can agree and everything will be fine.

Everybody remain calm!


:)

Joe

[MachSchnell]

Well, assuming the average person or even those not participating in cut tests can even tell a difference besides the placebo effect.

Edge geometry per knife is going to make a bigger difference than the nuances of a specific heat-treat. At least if it's within an acceptable range that is (ie not messed up). A Para2, Manix2, and BM 940 don't have similar grinds, blade shapes or even thicknesses so if you ask 10 people you won't get consistent opinions.

Yes, but when they all are set to 30 degrees inclusive, finished the same way, and worked on similar materials (granted it's not a controlled test) the Para just doesn't chip like the others mentioned... Placebo maybe, but this is real world experience; sure there are plenty of variables like slight differences in the material being cut and the heat treat, or it could just be dumb luck :confused: .

[Blerv]

It's one real world experience with two knives. Valid or not I wouldnt base a law on it or even a theory.

Internet dogma is tough to refute. Chippy S30v has been fighting an upward battle for years.