Testing Knives "Scientifically" - Lbs of Force

Got this idea from a blade maker when I was up at the Pacific Northwest Gathering on how to test knives by looking at lbs of force needed to cut a 25mm tall carrot with 25mm on each side. I did this is a rush today as I'm headed to Baja California tomorrow. I just wanted to spread this possible idea - would love to hear everyones thoughts on this and how it could be improved =)

This of course could also be measured on other types of product.

Preperation:
-All knives sharpened/stropped on a #3000 Chosera so that they can easily cut hanging tissue paper
-Carrots calipered at 25mm tall and 25mm on each side of the cutting location
-Carrots soaked for minimum of 30 minutes to help with consistency

Cutting
-Knives tested at 'natural' front area (approx front 1/3rd) and 'natural' back area of knife (approx back 1/3rd) -> different on each knife but whatever area felt natural to use
-Tested push cutting

Measurements
-Lbs of force measured as maximum lbs of force during cutting stroke
-All knives had 3 measurements and median taken (in the future would do more if I had more product)

I won't be disclosing the results of the knives I tested from custom makers without asking them first for permission. Currently the Kato is the best of the 3 knives I tested =)




Cheers,
Michael

Wait there was a Pacific NW gathering?! How do I get on the mailing list to find out about the next one?

richard said:

Wait there was a Pacific NW gathering?! How do I get on the mailing list to find out about the next one?

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Oh man wish you could have made it! Mareko had posted on the other forum and Ian posted here: http://www.kitchenknifeforums.com/showthread.php/27892-Pacific-Northwest-Gathering

Not to bum you out anymore but Bob Kramer was there...

Sheeyat

Don't mind me, please return to your regularly scheduled program

Interesting, but I cut many more things than carrots at the specified size...just because a knife cuts carrots the best, I don't see how the results could mean anything more than specifically that. I'm guessing that blade maker's knives cut carrots better than other produce

Bet the gathering was a blast...hope someone will follow-up with some pics.

chinacats said:

Interesting, but I cut many more things than carrots at the specified size...just because a knife cuts carrots the best, I don't see how the results could mean anything more than specifically that. I'm guessing that blade maker's knives cut carrots better than other items

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Lols that is possible though I actually picked carrots at 25mm since it is really easy to find carrots that height. Could also test on 40-50mm if I could find more. One thing I do want to test on but are super expensive is yams/sweet potatoes.

What are your general test products?

The general idea was just testing lbs of force as a cutting measurement.

I actually do like to cut a big fat carrot as one of the first items but if it will cut a carrot and not wedge (no matter the force), it may also have stiction issues so imo I know how a knife cuts by making soup or something along those lines that involve quite a few ingredients. I'm not knocking the test so much as saying it really doesn't say much about overall performance vs how it cuts a very specific (but relevant) product.

This is all kinds of cool. Very thorough Mike and I think it's a perfectly good test. Carrot, while not the only thing I cut tells me plenty about a knife. What was Bryan Raquin's gathering knife like?

I just read the thread and nearly self-immolated with jealousy and my Raquin question is answered. Feel a little bit of sellers regret now.

chinacats said:

I actually do like to cut a big fat carrot as one of the first items but if it will cut a carrot and not wedge (no matter the force), it may also have stiction issues so imo I know how a knife cuts by making soup or something along those lines that involve quite a few ingredients. I'm not knocking the test so much as saying it really doesn't say much about overall performance vs how it cuts a very specific (but relevant) product.

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Thanks for adding additional color, and I definitely agree. I wanted to add some more objective testing to knives. Currently it has confirmed what my hands have felt, though it is nice to put a number/ratio to that.

My general tests - potato (stiction/drag), carrot (wedging), yam (ability to cut very difficult/fibrous product), onion (general use/tip work)

Badgertooth said:

This is all kinds of cool. Very thorough Mike and I think it's a perfectly good test. Carrot, while not the only thing I cut tells me plenty about a knife. What was Bryan Raquin's gathering knife like?

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I find most custom makers do a decent job of preventing stiction so I usually only cut one potato to do a quick check then it is to the carrots / yams. I'll shoot you a PM about gathering stuff also =)

Also wanted to add one of the key reasons I wanted to test like this is to be able to tell how the geometry of a blade seperate from its weight. Cleavers for example always feel as they are cutting "better" for the same geometry as they have 5-8ozs of additional force being applied from the weight of the blade.

My general tests have been measuring knives in the 3lbs to 5lbs of force with consistency of measurements all being within 1-4ozs of previous measurements.

I do not get, what is the problem of disclosing custom makers knives's performance. If they suck, they suck and if not then they dont to put it in a perspective. Common, this "protectionist bs" is pure BS!

However, I like the test but need data more data....

Ruso said:

I do not get, what is the problem of disclosing custom makers knives's performance. If they suck, they suck and if not then they dont to put it in a perspective. Common, this "protectionist bs" is pure BS!

However, I like the test but need data more data....

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I will eventually share all results, but right now I feel my tests is still in its crude beta test phase and with only carrots may lead people down the wrong path.

I do plan on eventually once I refine the tests to post / share full results.

Mike, I appreciate your efforts to quantify what is largely qualitative data. My own experience with carrots is they vary too much in water content to be a meaningful subject.

I would think daikon would provide a better assessment for what you describe. More uniformity between products and more consistency through the product. These characteristics are why I use daikon as first vegetable in knife classes

Good tip dave! I do have quite a bit of daikon and it is quite cheap to get around here.

Would the soaking the carrots for 30 minutes to an hour not help with the water content or is it the density that is so different between? I was surprised at how consistent the 3 cuts where for each knife as I expected some more variance - I did not have a total difference of more than 4ozs.

daveb said:

Mike, I appreciate your efforts to quantify what is largely qualitative data. My own experience with carrots is they vary too much in water content to be a meaningful subject.

I would think daikon would provide a better assessment for what you describe. More uniformity between products and more consistency through the product. These characteristics are why I use daikon as first vegetable in knife classes

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Mike, I appreciate your efforts to quantify what is largely qualitative data. My own experience with carrots is they vary too much in water content to be a meaningful subject.

I would think daikon would provide a better assessment for what you describe. More uniformity between products and more consistency through the product. These characteristics are why I use daikon as first vegetable in knife classes

I think this is awesome! I can't wait to start playing with this test style. Will keep you informed!

Yah! Awesome to hear, one of the reasons I wanted to bring this up is a hope that it moves the performance standards up for the whole custom knife market =)

MaumasiFireArts said:

I think this is awesome! I can't wait to start playing with this test style. Will keep you informed!

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This test was originally performed by Roman Landes about 10 years ago..... He used a kitchen wage and a really big spud and an apple corer (all the testing things got the same size, and if you find a big spud for the test, it will last for a few knives to test......

Greets Sebastian.

Awesome history! Do you by chance have a link to his findings? I just took a quick look and couldn't find anything.

mikedtran said:

Awesome history! Do you by chance have a link to his findings? I just took a quick look and couldn't find anything.

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I don`t know if he ever published his findings, he just told me to do so.......

Here is some information about him:

http://www.apero-magazin.de/index.php?id=roman-landes0

He also wrote the bible for knifemakers :Messerklingen und Stahl......

https://www.amazon.de/dp/3938711043/?tag=skimlinks_replacement-20

sorry everything is in german language....

Greets Sebastian.