Is CRYO treatment the new edge packing

[Scaniaman]

There are differences between testing material properties and comparing user experience. For example, you wouldn’t ask a group of office workers if they can tell that the new building has higher strength steel in it. And if you had a 10% improvement in edge retention with some new steel or heat treatment the best way of finding an improvement would not be handing knives to 100 people and asking them to cut things.

I agree with you. Of course there is a difference in measuring component material properties and measuring the real life performance of the end-product. It goes without saying that you can't guarantee a better or longer lasting building just because you put higher strength steel in it. There are too many other variables involved in the end performance of that building.
If one wants to evaluate building "performance", and the part played by steel strength in it, by asking people sitting in those buildings, fine. But yeah, I'd probably choose another endpoint in that particular case..

Likewise a pharmaceutical company can't claim to prolong and increase the quality of peoples' lives, just because they make an anti-hypertensive agent that lower's blood pressure in a laboratory setting. We need a clinical (real life) trial for that.

It's all about what you're interested in measuring. I do think that the end user's actual experienced performance is a fair "end point" in such a study of knives, but I am open to better suggestions. ​

 

[Scaniaman]

Well, you'll have figure out what the standard of deviation is first that users will get with the same knives, with the same HT, blind test without them knowing they are different.
Might be difficult without a way to quantify that.
So, you'll have to figure out how to measure "user experience performance" into something quantifiable so you can have measurable differences.

God Speed.

You are right. But quantifying reported subjective experience is common in clinical trials, so I think something could be figured out.

 

[Scaniaman]

All good science require controlling and or limiting variables. Subjective experience is one of the lowest levels of evidence there is. It is useful in forming a hypothesis to test though, which fuelled my heat treat obsession seven years ago.

I am not talking about drawing conclusions from one person's subjective experince. I am talking of a randomized controlled study with grups of indivuduals. The subjective experience in those groups by no means has to be "low level of evidence". It depends on what you think is relevant to measure.

 

[Willie71]

I am not talking about drawing conclusions from one person's subjective experince. I am talking of a randomized controlled study with grups of indivuduals. The subjective experience in those groups by no means has to be "low level of evidence". It depends on what you think is relevant to measure.

the study design is by definition low level evidence.

 

[DeadboxHero]

Yup, figure it out.

You'll have to do it and show us.

Make it so.

You are right. But quantifying reported subjective experience is common in clinical trials, so I think something could be figured out.

You are right. But quantifying reported subjective experience is common in clinical trials, so I think something could be figured out.

 

[DevinT]

All steels have retained austenite, even simple carbon steels.

The higher the carbon and alloy the higher the RA.

Freeze treatments reduce or eliminate RA. Less RA = higher hardness.

Tempering reduces or eliminates RA especially when using the upper temper, like high speed steels.

Longer tempering times reduce RA.

The longer the delay, going from the quench to the freeze treatments, the deeper you need to cool to reduce or eliminate RA. That’s why large commercial heat treaters use LN2, they are slower at getting the blades into the cryo.

The trend right now is harden knives on the higher end for increased wear resistance.

The bigger the heat treating story, the higher the price of the knife.

JT does not know how to use the like button.

Hoss

 

[JTknives]

I have not figured out the use of the like button yet.

 

[Willie71]

All steels have retained austenite, even simple carbon steels.

The higher the carbon and alloy the higher the RA.

Freeze treatments reduce or eliminate RA. Less RA = higher hardness.

Tempering reduces or eliminates RA especially when using the upper temper, like high speed steels.

Longer tempering times reduce RA.

The longer the delay, going from the quench to the freeze treatments, the deeper you need to cool to reduce or eliminate RA. That’s why large commercial heat treaters use LN2, they are slower at getting the blades into the cryo.

The trend right now is harden knives on the higher end for increased wear resistance.

The bigger the heat treating story, the higher the price of the knife.

JT does not know how to use the like button.

Hoss

I haven’t been around as long as you, but I think part of the trend to going harder is because of Larrin’s testing, and using tools that give repeatable results. Rc58/59 is much safer if you are judging temps by eye, and dunking in used motor oil. With the kilns being used, cryo, low temper, the quality and consistency of the heat treat is much better, allowing the boundaries to be pushed. When we see steels that are tougher at Rc64/65 than O1 or 1095 at Rc60, it seems much less like voodoo to make knifes that hard.

 

[Scaniaman]

the study design is by definition low level evidence.

Yes there are limitations to looking at a single RCT. But can you suggest something better at this point? To my knowledge they are the best when wanting to take things from the lab to "real life".
Sure, a systematic review or meta-analysis would have a higher level of evidence. But how are going to make one of those when you have no RCTs to base them on?

 

[Scaniaman]

Yup, figure it out.

You'll have to do it and show us.

Make it so.

No, I don't have to do it and show to you, for the sake of my argument. It is an important question but I wouldn't let it take up too much room in the discussion at this stage. The thread topic isn't about, nor am I arguing for, a particular knife-user questionaire or interview format/content.

My point is, and what I am interested in knowing:

Can the user/customer/client significantly perceive the difference between - 120 deep freeze and cryo/LN2 in a blade, in real life usage?

Is this in any way controversial or unwanted knowledge to us?

I'm not saying the difference couldn't be perceived, so don't get me wrong.

To paraphrase and be extra clear: It is one thing to discuss the technical setup and design of such a trial. It is another thing to think that a well designed and excecuted trial of such sort would be of interest and value = what I am saying /arguing.

 

[Randydb]

You guys and your understanding of what is going on and your ability to test it really impresses me. I read these threads and Larin's articles and I feel like I am learning a second language and I only know three or four words so far. On one hand I find this knowledge and ability to achieve impressive levels of quality really cool. Then I step back once in a while and realize that the vast majority of the end users wouldn't be able to even recognize the nuanced changes/differences if they weren't told they were there. I'm not saying don't do it though, I'm just thinking of how some things are lost on the end user.
I used to see similar things in the drum building world. Builders would be chasing all sorts of different qualities from bearing edge, to tone of wood to "nodal interference." But 9999 out of 10000 end users would never be able to consistently recognize the differences or qualities that had been built into those drums if they weren't told about them
.

 

[Kevin Wilkins]

Cryo is well researched and used in industry.

Edge packing was basically bro science in action.

BRO-SCIENCE! That's one I haven't heard!! Perfect!!! Got to remember that one. Like chugging Clorox to fight disease! Yeah! Bro Science!

 

[Pinoy Knife]

No, I don't have to do it and show to you, for the sake of my argument. It is an important question but I wouldn't let it take up too much room in the discussion at this stage. The thread topic isn't about, nor am I arguing for, a particular knife-user questionaire or interview format/content.

My point is, and what I am interested in knowing:

Can the user/customer/client significantly perceive the difference between - 120 deep freeze and cryo/LN2 in a blade, in real life usage?

Is this in any way controversial or unwanted knowledge to us?

I'm not saying the difference couldn't be perceived, so don't get me wrong.

To paraphrase and be extra clear: It is one thing to discuss the technical setup and design of such a trial. It is another thing to think that a well designed and excecuted trial of such sort would be of interest and value = what I am saying /arguing.

so i think you are asking if anyone has done testing to see a fact based point on the difference of Cryo versus non cryo ?? the biggest problem with that is that Everyone holds a knife or object slightly different and may apply pressure differently when cutting ,therefore getting reliable data from usage can be challenging .
i think this is why the CATRA machine is used . it does the exact same thing over and over to provide those results..
of course i may be wrong but that is the opinion i have about Why that is used ..

 

[Scaniaman]

so i think you are asking if anyone has done testing to see a fact based point on the difference of Cryo versus non cryo ?? the biggest problem with that is that Everyone holds a knife or object slightly different and may apply pressure differently when cutting ,therefore getting reliable data from usage can be challenging .
i think this is why the CATRA machine is used . it does the exact same thing over and over to provide those results..
of course i may be wrong but that is the opinion i have about Why that is used ..

Yes very challenging, and it is a lot due to these individual variations that it is hard to extrapolate laboratory findings on real life circumstance. This is a reason why we do huge trials when it comes to pharmaceuticals.

Another idea, to somewhat accomodate such variations, would be to let participants use all three knives (cryo/ln2, -120 deep freeze, no freeze at all). Still double blinded of course, and report back.

 

[Natlek]

In Catra test even thinnest and hardest edge will not chip.............

 

[Josh Rider]

I would think a line chef or someone that’s making cuts all day long would notice a difference in how long I can cut before it needs to be re-sharpened.
Whether or not someone would notice a performance difference isn’t really the right way to look at it though in my opinion.

 

[Willie71]

Yes there are limitations to looking at a single RCT. But can you suggest something better at this point? To my knowledge they are the best when wanting to take things from the lab to "real life".
Sure, a systematic review or meta-analysis would have a higher level of evidence. But how are going to make one of those when you have no RCTs to base them on?

The inverse is typically true. We have controlled charpy and Catra studies that came after real world use generated hypothesis.

in your example with the anti hypertensives, the flow would be from subjective to less subjective. How someone reports they feel has to be backed up with actual blood pressure readings. Extrapolating life expectancy without controlling for other variables is meaningless.

We have to control for placebo effect.

 

[Larrin]

You guys and your understanding of what is going on and your ability to test it really impresses me. I read these threads and Larin's articles and I feel like I am learning a second language and I only know three or four words so far. On one hand I find this knowledge and ability to achieve impressive levels of quality really cool. Then I step back once in a while and realize that the vast majority of the end users wouldn't be able to even recognize the nuanced changes/differences if they weren't told they were there. I'm not saying don't do it though, I'm just thinking of how some things are lost on the end user.
I used to see similar things in the drum building world. Builders would be chasing all sorts of different qualities from bearing edge, to tone of wood to "nodal interference." But 9999 out of 10000 end users would never be able to consistently recognize the differences or qualities that had been built into those drums if they weren't told about them
.

The purpose of learning about steel and heat treating is not to overcomplicate, add extra steps, or chase infinitesimally small improvements. Instead it is to understand which parameters are the most important, how to optimize heat treatments, and to understand the mechanisms at work so when someone says, "you can't make a good knife without cryo" you know what elements of that statement are true and which are not. To make things simple sometimes you have to understand many aspects that may appear unimportant. If knifemakers wanted to follow heat treatment recipes there would perhaps be less to understand. But as long as we have people asking, "Why can't I just heat treat with my torch?" or "Does XXXX steel need cryo?" or "Should I be triple quenching my steel?" there is more education required to answer those questions. So there is a balance between knifemakers who are frustrated by over-information and say, "Just tell me what to do," and all of those "creative" knifemakers trying to do things that don't make sense, or chasing optimizations that make no perceptible difference because of misunderstanding of how things work. I fall on the side of more information is better, though in the end the decision-making is not that complicated. It takes more information to be able to make simple decisions.

 

[DevinT]

One very practical reason to use cryo is that the burr formed during sharpening is much easier to remove with cryo than without.

Most knife makers don’t know how to sharpen, and most knife users are even worse.

Hoss

 

[weo]

The purpose of learning ... is not to over complicate, add extra steps, ... Instead it is to understand which parameters are the most important, how to optimize ...to understand the mechanisms at work so when someone says, "you can't ..." you know what elements of that statement are true and which are not. To make things simple sometimes you have to understand many aspects that may appear unimportant... But as long as we have people asking, "Why..." or "Does ..." or "Should I be ..." there is more education required to answer those questions. So there is a balance... I fall on the side of more information is better, though in the end the decision-making is not that complicated. It takes more information to be able to make simple decisions.

So true about most things.