"HRC as advertised." Who is accurately listing HRC?

Discuss Spyderco's products and history.
Banter 247
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Re: "HRC as advertised." Who is accurately listing HRC?

#101

Post by Banter 247 »

I’m very interested in predictable, and repeatable information.

With that... my friend Gerald at Outpost76 does edge retention tests cutting cardboard. He uses a set progression for sharpening, tapes off a 1” section to concentrate the test, and cuts until a catch or dulling causes the knife to stop cleanly slicing paper. Once the test is over, he does it again, to see if the result falls in a comparable range to the first. He repeats this until the results stabilize. This is predictably, repeatably within 2-4 tests. Once the results stabilize, they continue to fall within the same range from that point forward.

Supersteel Steve and Tom Hosang Outdoors use similar methodology.

In their testing, there are of course variables at play, so what we look for isn’t an exact number of cuts. It’s a range.

With that, we’ve consistently seen most S30V, S35VN, M390, 204P, and 20CV fall within the same range. This correlated to the general trend of production M390/20CV/204P falling between 58-59hrc in that testing. Samples tested for hrc and edge retention have seemed to support this.

A PM2 went for hrc testing and hit 62. Gerald tested it against cardboard, and it effectively doubled the performance of the same steel in a sample tested at 59hrc. He repeated the test three times, and the results were very similar each time.

He then got two more knives in M390, from Reate, and tested them, again repeating the testing to validate results. These also blew away the majority of previously tested M390/20CV/204P, as well as all tested S30V and S35VN, falling closer to the PM2.

Those are now being sent out for hrc testing.

The prediction here is that they hit around 61.

Maybe we’re right. Maybe we’re wrong.

What is my point?

We live in a world of variables. Rather than getting lost talking about all that those are, we’re finding predictable, repeatable things first, and working from there.

To that end, Gerald has a lot of M390 coming his way to explore hrc to edge retention result ranges. We understand fully that structure within the steel is also a factor, and that many variables are at play. Still, within the context of this testing, we’re predicting a strong correlation.

It’s going to be interesting seeing this develop.
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Re: "HRC as advertised." Who is accurately listing HRC?

#102

Post by Ankerson »

Cardboard really isn't that great of a media to use, it varies greatly.

Manila rope is MUCH better and more stable and consistent.

But then you said you are looking for a range and not exact numbers so it's fine to get a general idea.

I wouldn't put too much stock in the results using that method however.

You could use a more accurate method of testing, but then manila rope isn't free or cheap for that matter.

Sounds like they are using polished edges too and sharpening freehand I am guessing?

And with no real set beginning point measuring sharpness that's repeatable?

And no real ending point that is repeatable, something that can be measured?
Last edited by Ankerson on Thu Jun 20, 2019 10:58 pm, edited 1 time in total.
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Re: "HRC as advertised." Who is accurately listing HRC?

#103

Post by Naperville »

.
Last edited by Naperville on Wed Oct 30, 2019 6:51 pm, edited 1 time in total.
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Re: "HRC as advertised." Who is accurately listing HRC?

#104

Post by Banter 247 »

Ankerson wrote:
Thu Jun 20, 2019 10:43 pm
Cardboard really isn't that great of a media to use, it varies greatly.

Manila rope is MUCH better and more stable and consistent.

But then you said you are looking for a range and not exact numbers so it's fine to get a general idea.

I wouldn't put too much stock in the results using that method however.

You could use a more accurate method of testing, but then manila rope isn't free or cheap for that matter.

Sounds like they are using polished edges too and sharpening freehand I am guessing?

And with no real set beginning point measuring sharpness that's repeatable?

And no real ending point that is repeatable, something that can be measured?
Despite all of the variables, predictable, repeatable results emerge. It’s not down to the single cut, but it provides a notable stratification.
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Re: "HRC as advertised." Who is accurately listing HRC?

#105

Post by Ankerson »

Naperville wrote:
Thu Jun 20, 2019 10:56 pm
Ankerson wrote:
Thu Jun 20, 2019 10:43 pm
Cardboard really isn't that great of a media to use, it varies greatly.

Manila rope is MUCH better and more stable and consistent.

But then you said you are looking for a range and not exact numbers so it's fine to get a general idea.

I wouldn't put too much stock in the results using that method.

You could use a more accurate method of testing, but then manila rope isn't free or cheap for that matter.
Just my opinion, but if I were getting in to testing knife blades I would take the money that I would spend on manila rope or cardboard and buy a Bess testing system.

I know that you used a Bess testing system. Did you eventually purchase one?

I have a BESS sharpness tester. I use it to verify what I already know, or to confirm it, the starting sharpness.

Other than that I still test the way I always have cutting rope on a scale and it can be accurate and repeatable within 20 cuts in my experience. I have tested the some of the same knives over with a month or more time frame and have gotten the same or within 20 cuts of the 1st test. (Production blades)

I doubt that I will change that as I haven't seen or heard of anything better other than CATRA.

I have a set beginning and ending point, that never changes, I stop at a measured 20 LBS of downforce.

All knives are reprofiled to 15 DPS sharpened exactly the same on the EDGE PRO using the same Congress Mold Master stones finishing at 400 grit.

I use high quality manila rope that is very consistent.

My results are not set in stone however, but it is the best that I can do by hand, I wouldn't say the results are absolute so don't take my numbers as the end all beat all of anything. All it is really is a general guide of performance.

CATRA is still the best and most accurate by far.
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Re: "HRC as advertised." Who is accurately listing HRC?

#106

Post by ZrowsN1s »

Your testing has been a huge value and contribution to the community Jim. That's a huge chunk of your time that you've shared with us (not to mention the money you've spent on rope).
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Re: "HRC as advertised." Who is accurately listing HRC?

#107

Post by Chris_P_Bacon »

For the new guys, hope this helps at least one of you. Old timers feel free to skip to the next post.

What some are stressing about is, they don't want you to fall into a mode of thinking where you simply compare knives based on their respective HT/RC (Heat Treat/Rockwell Hardness) numbers alone. It's only part of the picture which also affects cutting ability (an important part none the less).

Spyderco as a Brand, does a solid job with quality control in this area. The numbers are not shown in the specs sheets (currently). I've seen speculation it's a "trade secret". Personally, I don't believe that, allow me to explain.

Take extreme custom makers who generally do smaller batches Phil Wilson, BBB, Bluntcut, etc. A single knife or even a few at a time, can quickly and easily be moved by hand, from heat to quench, cyro, tempering, resulting in tighter control over the time, temp and final RC. Has to do with how fast they're able to move a few pieces from here to there. These elapsed times are crutial when pushing the extremes.

Contrast that to the mass production world, where you have a 1200 piece run (or more), picture mulitple large racks of knives so heavy you need a mechanical advantage to move them . By nature moving from step one to step two, etc is simply a slower process, resulting in greater fluctuations.

I believe Spyderco doesn't publish the RC because of the unavoidable fluctuations that happen with Mass Production. Yours might test out at 62 and your buddy's exact same model at 61. Had they advertised 62 in the spec sheet, he may be tempted to try and swap his out. This could open a can of worms like the subway 12" sandwich fiasco. Funny thing is he might find one part of his blade tested 60 another part at 61, yes were talking same blade here. Not uncommon.

But, hardly a trade secret when anyone (at anytime) is free to send different models in for independant testing and tell the world!
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Re: "HRC as advertised." Who is accurately listing HRC?

#108

Post by Pelagic »

I like that Jim uses a scale. Not only because it's unique in that it takes a step towards testing cutting ability over sharpness, but for the fact that he's reducing a variable amongst tests using manilla rope. When most people cut rope they use a cutting board, so with every cut they are slamming the apex into hardwood. At least with the scale there's a central focus on the amount of force used, so once the cut is made, no unnecessary force is added when the apex makes contact with the cutting board.
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Re: "HRC as advertised." Who is accurately listing HRC?

#109

Post by sal »

ZrowsN1s wrote:
Thu Jun 20, 2019 11:50 pm
Your testing has been a huge value and contribution to the community Jim. That's a huge chunk of your time that you've shared with us (not to mention the money you've spent on rope).
Not to mention the physical wear and tear on hands and arms.

sal
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Re: "HRC as advertised." Who is accurately listing HRC?

#110

Post by ZrowsN1s »

^^^Truth!
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Re: "HRC as advertised." Who is accurately listing HRC?

#111

Post by Naperville »

.
Last edited by Naperville on Wed Oct 30, 2019 6:51 pm, edited 1 time in total.
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Re: "HRC as advertised." Who is accurately listing HRC?

#112

Post by Gsg9 »

https://youtu.be/eH1vP4bDlto
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Re: "HRC as advertised." Who is accurately listing HRC?

#113

Post by shunsui »

Well that's not Nick Shabazz.

Let's try this.

https://youtu.be/6lXNLzru8XU
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Re: "HRC as advertised." Who is accurately listing HRC?

#114

Post by Banter 247 »

shunsui wrote:
Sun Jun 23, 2019 5:49 am
Well that's not Nick Shabazz.

Let's try this.

https://youtu.be/6lXNLzru8XU
Note:

Nick reached out to Kurt/jcoolg19 before posting the video, and subsequently confirmed via IG and YT comments, as well as directly to me, that the video was not directed at us as a group, and was specifically trying to caution against copycat attempts by people who aren’t equipped to test properly. Nick has wisely encouraged caution. People had been talking about getting scratch kits and the like, which isn’t ideal.

Frankly, I think Nick did a beautiful job with the video. One of the big issues with the conversation as a whole is getting people to slow down and differentiate between what the data tells us, and what it does not tell us.
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Re: "HRC as advertised." Who is accurately listing HRC?

#115

Post by Ankerson »

Not really sure how or why this focus on HRC has become THAT thing.

Goes back to what I said before, as the old saying goes.....

"Numbers are the devils playground." ;)

If a knife performs well and or does what it's supposed to do then it's a good knife.

There are many factors that effect knife performance to consider:

  • Does it cut or perform well?, if not then why?

    Is the geometry too thick or too thin?
    Poor sharpening?
    Wrong edge profile for the job?
    Poor blade design for the job?
    Wrong tool for the job?
    Wrong edge finish for the job?
    Poor cutting technique?
    Wrong steel for the job?
All of the above things are important and should be considered also.

Notice I didn't list HRC hardness?

The reason is the above can and will have a larger effect on performance than just the HRC value. ;)




Goes back to what someone said about the Megapixel thing with DSLR's.

The MORE the better?

Not really because it's much more complicated than just how many Megapixels the DSLR is rated at.

Even the entry level DSLR's are 24 MP these days so it really doesn't mean a whole lot.

Can an entry level DSLR take good photos? Yeah even a $5 box camera can do that once in awhile.

Yes in the hands of a Pro the entry level cameras can take good photos, notice I said in the hands of a Pro that knows how to squeeze the very best out of the camera. You see that in the reviews, just remember who it is and what they are taking those photos. ;)

For the masses they are fine since MOST just use AUTO anyway, that's the point and shoot mode or as some of us say the Waiter Mode were you hand the camera to the waiter and tell them to push the silver button. The photo may or may not be good, or as good as it could have been.

The issue is that the entry level cameras are limited, some are very limited depending on what is really needed. The Auto Focus really isn't as good as the higher end cameras nor is the image sensor.

All I am saying is get the right tool for the job and learn how to use it as best as you can, but don't expect miracles to happen unless you put in the work and the time.

You can take a $8,000 camera, put it on AUTO using crap kit lenses and end up with junk photos.
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Re: "HRC as advertised." Who is accurately listing HRC?

#116

Post by Banter 247 »

Ankerson wrote:
Sun Jun 23, 2019 10:05 am
Not really sure how or why this focus on HRC has become THAT thing.

Goes back to what I said before, as the old saying goes.....

"Numbers are the devils playground." ;)

If a knife performs well and or does what it's supposed to do then it's a good knife.

There are many factors that effect knife performance to consider:

  • Does it cut or perform well?, if not then why?

    Is the geometry too thick or too thin?
    Poor sharpening?
    Wrong edge profile for the job?
    Poor blade design for the job?
    Wrong tool for the job?
    Wrong edge finish for the job?
    Poor cutting technique?
    Wrong steel for the job?
All of the above things are important and should be considered also.

Notice I didn't list HRC hardness?

The reason is the above can and will have a larger effect on performance than just the HRC value. ;)




Goes back to what someone said about the Megapixel thing with DSLR's.

The MORE the better?

Not really because it's much more complicated than just how many Megapixels the DSLR is rated at.

Even the entry level DSLR's are 24 MP these days so it really doesn't mean a whole lot.

Can an entry level DSLR take good photos? Yeah even a $5 box camera can do that once in awhile.

Yes in the hands of a Pro the entry level cameras can take good photos, notice I said in the hands of a Pro that knows how to squeeze the very best out of the camera. You see that in the reviews, just remember who it is and what they are taking those photos. ;)

For the masses they are fine since MOST just use AUTO anyway, that's the point and shoot mode or as some of us say the Waiter Mode were you hand the camera to the waiter and tell them to push the silver button. The photo may or may not be good, or as good as it could have been.

The issue is that the entry level cameras are limited, some are very limited depending on what is really needed. The Auto Focus really isn't as good as the higher end cameras nor is the image sensor.

All I am saying is get the right tool for the job and learn how to use it as best as you can, but don't expect miracles to happen unless you put in the work and the time.

You can take a $8,000 camera, put it on AUTO using crap kit lenses and end up with junk photos.
I think it’s because, within the context of common production knife variable ranges, it overpowers most of those variables.

So... if I take 20 knives, from different manufacturers, and put the same secondary edge angle on them, with the same edge finish, and the same composition, 10 of them being 204P at 59 hrc, and 10 of them being 204P at 62hrc, and use 1” sections of the blades, with 3 different testers holding them, cutting single wall cardboard, it’s predictable and repeatable that the 62hrc samples will out cut the 59hrc samples, despite the variables in place.

It would be an anomaly to see a deviation, and exploring that would likely lead to discovering a badly blown ht process, or some other glaring issue.
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Re: "HRC as advertised." Who is accurately listing HRC?

#117

Post by Ankerson »

Banter 247 wrote:
Sun Jun 23, 2019 12:46 pm
Ankerson wrote:
Sun Jun 23, 2019 10:05 am
Not really sure how or why this focus on HRC has become THAT thing.

Goes back to what I said before, as the old saying goes.....

"Numbers are the devils playground." ;)

If a knife performs well and or does what it's supposed to do then it's a good knife.

There are many factors that effect knife performance to consider:

  • Does it cut or perform well?, if not then why?

    Is the geometry too thick or too thin?
    Poor sharpening?
    Wrong edge profile for the job?
    Poor blade design for the job?
    Wrong tool for the job?
    Wrong edge finish for the job?
    Poor cutting technique?
    Wrong steel for the job?
All of the above things are important and should be considered also.

Notice I didn't list HRC hardness?

The reason is the above can and will have a larger effect on performance than just the HRC value. ;)




Goes back to what someone said about the Megapixel thing with DSLR's.

The MORE the better?

Not really because it's much more complicated than just how many Megapixels the DSLR is rated at.

Even the entry level DSLR's are 24 MP these days so it really doesn't mean a whole lot.

Can an entry level DSLR take good photos? Yeah even a $5 box camera can do that once in awhile.

Yes in the hands of a Pro the entry level cameras can take good photos, notice I said in the hands of a Pro that knows how to squeeze the very best out of the camera. You see that in the reviews, just remember who it is and what they are taking those photos. ;)

For the masses they are fine since MOST just use AUTO anyway, that's the point and shoot mode or as some of us say the Waiter Mode were you hand the camera to the waiter and tell them to push the silver button. The photo may or may not be good, or as good as it could have been.

The issue is that the entry level cameras are limited, some are very limited depending on what is really needed. The Auto Focus really isn't as good as the higher end cameras nor is the image sensor.

All I am saying is get the right tool for the job and learn how to use it as best as you can, but don't expect miracles to happen unless you put in the work and the time.

You can take a $8,000 camera, put it on AUTO using crap kit lenses and end up with junk photos.
I think it’s because, within the context of common production knife variable ranges, it overpowers most of those variables.

So... if I take 20 knives, from different manufacturers, and put the same secondary edge angle on them, with the same edge finish, and the same composition, 10 of them being 204P at 59 hrc, and 10 of them being 204P at 62hrc, and use 1” sections of the blades, with 3 different testers holding them, cutting single wall cardboard, it’s predictable and repeatable that the 62hrc samples will out cut the 59hrc samples, despite the variables in place.

It would be an anomaly to see a deviation, and exploring that would likely lead to discovering a badly blown ht process, or some other glaring issue.


Not really. ;)

Cardboard is very unpredictable and varies way too much to really use as a testing media for any sort of real data points comparing steels and or knives.

I have seen cardboard that will dull knives in a VERY short time.

Doesn't matter how many times you test or do runs if the variables aren't cut down to the min.

The reason why we don't use it for any sort of serious data collection.

Unless you were to go to a cardboard factory and have it made special so it's all the same to cut it down and even then...

Change the method and cut down the variables to a min and you will see how inaccurate it really is.

Throwing more numbers at something doesn't make the results more accurate if the base method is not accurate in the 1st place.

What you end up with bad data based on a scope that is too wide in the 1st place because there are too many variables.

It all just ends up as more bad data on top of bad data.
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Re: "HRC as advertised." Who is accurately listing HRC?

#118

Post by Banter 247 »

Ankerson wrote:
Sun Jun 23, 2019 12:52 pm
Banter 247 wrote:
Sun Jun 23, 2019 12:46 pm
Ankerson wrote:
Sun Jun 23, 2019 10:05 am
Not really sure how or why this focus on HRC has become THAT thing.

Goes back to what I said before, as the old saying goes.....

"Numbers are the devils playground." ;)

If a knife performs well and or does what it's supposed to do then it's a good knife.

There are many factors that effect knife performance to consider:

  • Does it cut or perform well?, if not then why?

    Is the geometry too thick or too thin?
    Poor sharpening?
    Wrong edge profile for the job?
    Poor blade design for the job?
    Wrong tool for the job?
    Wrong edge finish for the job?
    Poor cutting technique?
    Wrong steel for the job?
All of the above things are important and should be considered also.

Notice I didn't list HRC hardness?

The reason is the above can and will have a larger effect on performance than just the HRC value. ;)




Goes back to what someone said about the Megapixel thing with DSLR's.

The MORE the better?

Not really because it's much more complicated than just how many Megapixels the DSLR is rated at.

Even the entry level DSLR's are 24 MP these days so it really doesn't mean a whole lot.

Can an entry level DSLR take good photos? Yeah even a $5 box camera can do that once in awhile.

Yes in the hands of a Pro the entry level cameras can take good photos, notice I said in the hands of a Pro that knows how to squeeze the very best out of the camera. You see that in the reviews, just remember who it is and what they are taking those photos. ;)

For the masses they are fine since MOST just use AUTO anyway, that's the point and shoot mode or as some of us say the Waiter Mode were you hand the camera to the waiter and tell them to push the silver button. The photo may or may not be good, or as good as it could have been.

The issue is that the entry level cameras are limited, some are very limited depending on what is really needed. The Auto Focus really isn't as good as the higher end cameras nor is the image sensor.

All I am saying is get the right tool for the job and learn how to use it as best as you can, but don't expect miracles to happen unless you put in the work and the time.

You can take a $8,000 camera, put it on AUTO using crap kit lenses and end up with junk photos.
I think it’s because, within the context of common production knife variable ranges, it overpowers most of those variables.

So... if I take 20 knives, from different manufacturers, and put the same secondary edge angle on them, with the same edge finish, and the same composition, 10 of them being 204P at 59 hrc, and 10 of them being 204P at 62hrc, and use 1” sections of the blades, with 3 different testers holding them, cutting single wall cardboard, it’s predictable and repeatable that the 62hrc samples will out cut the 59hrc samples, despite the variables in place.

It would be an anomaly to see a deviation, and exploring that would likely lead to discovering a badly blown ht process, or some other glaring issue.


Not really. ;)

Cardboard is very unpredictable and varies way too much to really use as a testing media for any sort of real data points comparing steels and or knives.

I have seen cardboard that will dull knives in a VERY short time.

Doesn't matter how many times you test or do runs if the variables aren't cut down to the min.

The reason why we don't use it for any sort of serious data collection.
If the pattern holds up 100 times, yielding a range of stratification, then I would argue that it would indicate that hrc is one of multiple factors that is worth talking about. We don’t need a hard number, just a predictable, repeatable pattern.
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Re: "HRC as advertised." Who is accurately listing HRC?

#119

Post by Ankerson »

Banter 247 wrote:
Sun Jun 23, 2019 1:15 pm
Ankerson wrote:
Sun Jun 23, 2019 12:52 pm
Banter 247 wrote:
Sun Jun 23, 2019 12:46 pm
Ankerson wrote:
Sun Jun 23, 2019 10:05 am
Not really sure how or why this focus on HRC has become THAT thing.

Goes back to what I said before, as the old saying goes.....

"Numbers are the devils playground." ;)

If a knife performs well and or does what it's supposed to do then it's a good knife.

There are many factors that effect knife performance to consider:

  • Does it cut or perform well?, if not then why?

    Is the geometry too thick or too thin?
    Poor sharpening?
    Wrong edge profile for the job?
    Poor blade design for the job?
    Wrong tool for the job?
    Wrong edge finish for the job?
    Poor cutting technique?
    Wrong steel for the job?
All of the above things are important and should be considered also.

Notice I didn't list HRC hardness?

The reason is the above can and will have a larger effect on performance than just the HRC value. ;)




Goes back to what someone said about the Megapixel thing with DSLR's.

The MORE the better?

Not really because it's much more complicated than just how many Megapixels the DSLR is rated at.

Even the entry level DSLR's are 24 MP these days so it really doesn't mean a whole lot.

Can an entry level DSLR take good photos? Yeah even a $5 box camera can do that once in awhile.

Yes in the hands of a Pro the entry level cameras can take good photos, notice I said in the hands of a Pro that knows how to squeeze the very best out of the camera. You see that in the reviews, just remember who it is and what they are taking those photos. ;)

For the masses they are fine since MOST just use AUTO anyway, that's the point and shoot mode or as some of us say the Waiter Mode were you hand the camera to the waiter and tell them to push the silver button. The photo may or may not be good, or as good as it could have been.

The issue is that the entry level cameras are limited, some are very limited depending on what is really needed. The Auto Focus really isn't as good as the higher end cameras nor is the image sensor.

All I am saying is get the right tool for the job and learn how to use it as best as you can, but don't expect miracles to happen unless you put in the work and the time.

You can take a $8,000 camera, put it on AUTO using crap kit lenses and end up with junk photos.
I think it’s because, within the context of common production knife variable ranges, it overpowers most of those variables.

So... if I take 20 knives, from different manufacturers, and put the same secondary edge angle on them, with the same edge finish, and the same composition, 10 of them being 204P at 59 hrc, and 10 of them being 204P at 62hrc, and use 1” sections of the blades, with 3 different testers holding them, cutting single wall cardboard, it’s predictable and repeatable that the 62hrc samples will out cut the 59hrc samples, despite the variables in place.

It would be an anomaly to see a deviation, and exploring that would likely lead to discovering a badly blown ht process, or some other glaring issue.


Not really. ;)

Cardboard is very unpredictable and varies way too much to really use as a testing media for any sort of real data points comparing steels and or knives.

I have seen cardboard that will dull knives in a VERY short time.

Doesn't matter how many times you test or do runs if the variables aren't cut down to the min.

The reason why we don't use it for any sort of serious data collection.
If the pattern holds up 100 times, yielding a range of stratification, then I would argue that it would indicate that hrc is one of multiple factors that is worth talking about. We don’t need a hard number, just a predictable, repeatable pattern.

Not really because it's all based on a method that has too many variables to begin with.

So you have bad data to begin with and then pile more bad data on top of that.

The results scope is too wide with all of the variables to be even remotely accurate enough to be valid as far as serious testing goes.

Doesn't matter if you run it 1,000 times.

Adding more numbers doesn't make it more accurate.

Removing the variables makes it more accurate.
Banter 247
Member
Posts: 40
Joined: Mon Jun 03, 2019 7:56 am

Re: "HRC as advertised." Who is accurately listing HRC?

#120

Post by Banter 247 »

Am I understanding correctly that you’re saying that:

Same composition
higher hrc
Same secondary edge angle

Consistently out performing

Same composition
Same secondary edge angle
Lower hrc

To a point where I can predict that it will happen again, and replicate it

Despite

Cardboard variability
Different user

That the ability to accurately predict the result has no value?
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