Chippy Knives and Toughness: How Low Can You Go?

[Luftmensch]

I attribute this mostly to not having much extraneous lateral force when I'm cutting.

This is the crux of the problem. I believe that most large chips, outside of dropping and banging knives into sinks or during shipping, happen from bad technique, lateral and twisting forces. I have no way of proving it though.

I agree.

I dont have many data points (at all)... But my limited experience (and gut hunch) is that kitchen knives that are 'fragile' on paper, can still be reliable if used right.

I am willing to treat this null result as an 'evidence of absence' sort of thing....(the knife is not chipping or rolling so it is 'tough')... That said, I am not willing to deliberately disproof the prove the point by introducing negative evidence

I have no way of proving it though.

But logical arguments can be appealing! Force vectors that occur on the plane running through the middle of the blade can distribute strain throughout the body of the knife. This means the stress in the material can be spread over a larger volume. Forces that act off this plane have less supporting material to absorb the energy. The worse case would be applying a force laterally/perpendicular to the very edge.... there is little material to support this strain. The internal stress becomes very large and can quickly exceed the yield strength or ultimate tensile strength of the material.

I think this is roughly correct ... could be wrong...

 

[HumbleHomeCook]

Yes, the impact and fatigue tests in your book were quite the eye-opener for me.

I could certainly be wrong but I think what was said was that your research is not specific to kitchen knives but rather related to all knives however I certainly could have misinterpreted that. It's good to know you had specifically kitchen knives in mind when making your steel recommendation table. I always interpreted that table a little differently as being general recommendations for all knives.

I'm surely not going to speak for @Larrin , but that's not how I understood his comment. I took his response to mean, he's just testing steel and properties and then we can consider how they apply to applications. When thinking of kitchen knives, he thinks of balanced steels. Not that his recommendations are specifically kitchen knife oriented.

 

[Luftmensch]

Once you know your own personal lower limit I think the chart that @Larrin already covers the bases on what works for you.

... true... I am just seeking confirmation bias

Like I said earlier... I am willing to estimate 3 or 4 ft-lbs is enough in my hands in my kitchen....

I have my eyes set on a different topic for my credits-related projects.

Dont say something interesting like that... somebody might be compelled to ask further questions!

 

[Barmoley]

I agree.

I dont have many data points (at all)... But my limited experience (and gut hunch) is that kitchen knives that are 'fragile' on paper, can still be reliable if used right.

I am willing to treat this null result as an 'evidence of absence' sort of thing....(the knife is not chipping or rolling so it is 'tough')... That said, I am not willing to deliberately disproof the prove the point by introducing negative evidence




But logical arguments can be appealing! Force vectors that occur on the plane running through the middle of the blade can distribute strain throughout the body of the knife. This means the stress in the material can be spread over a larger volume. Forces that act off this plane have less supporting material to absorb the energy. The worse case would be applying a force laterally/perpendicular to the very edge.... there is little material to support this strain. The internal stress becomes very large and can quickly exceed the yield strength or ultimate tensile strength of the material.

I think this is roughly correct ... could be wrong...

I don't disagree, but logical arguments are not proof. Also, just because something makes sense in my head doesn't mean that it is actually true or that the world works that way . This is why Larrin, Shawn and others are such great resources.

 

[Luftmensch]

I don't disagree, but logical arguments are not proof. Also, just because something makes sense in my head doesn't mean that it is actually true or that the world works that way . This is why Larrin, Shawn and others are such great resources.

Hehe! No doubt!!

 

[Troopah_Knives]

I'm surely not going to speak for @Larrin , but that's not how I understood his comment. I took his response to mean, he's just testing steel and properties and then we can consider how they apply to applications. When thinking of kitchen knives, he thinks of balanced steels. Not that his recommendations are specifically kitchen knife oriented.

Reading it again I think you are right. I think

Very weird to hear my writing described as not applying to kitchen knives.

just tripped me up and got me primed to think that he was saying that it was directly kitchen knife-related. Just a misread on my part.

Dont say something interesting like that... somebody might be compelled to ask further questions!

I'm trying my best to keep this thread on the topic.

Also, just because something makes sense in my head doesn't mean that it is actually true or that the world works that way .

Setting aside both your and @Luftmensch explanations for the mechanisms why I think the statement that lateral forces are more likely to cause chipping is largely uncontroversial but maybe I'm missing something.

 

[ian]

Setting aside both your and @Luftmensch explanations for the mechanisms why I think the statement that lateral forces are more likely to cause chipping is largely uncontroversial but maybe I'm missing something.

Heh I witnessed this a couple days ago on the grinder with a thin-ish edge held horizontal and perpendicular to the platen. POW!!! 5mm round hole in the edge. (I was changing a nakiri into a santoku, so this was not a bad thing.)

 

[Barmoley]

Reading it again I think you are right. I think just tripped me up and got me primed to think that he was saying that it was directly kitchen knife-related. Just a misread on my part.



I'm trying my best to keep this thread on the topic.



Setting aside both your and @Luftmensch explanations for the mechanisms why I think the statement that lateral forces are more likely to cause chipping is largely uncontroversial but maybe I'm missing something.

My comment was about me not having proof that technique maters more than we give it credit and that it partially explains why different users have very different experiences with seemingly same knives. This is besides all the other reasons we've already discussed.