# Definitions of stiction , food release & wedging



## Geo87 (Apr 29, 2015)

It popped up in another thread some of these terms get thrown around and perhaps sometimes people confuse one for the other.
Anyone with better litteracy skills than me care to define them?


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## Rayuela (Apr 29, 2015)

Stiction describes the propensity of foods to stick to your knife when cutting, though it is a property of the knife, not the foodstuff.
Food release relates to much the same phenomenon, but is more open-ended. It describes the propensity of foods to stick to your knife, or not.
Wedging is a phenomenon whereby the food being cut (typically a hard thing like a carrot, potato or squash) cracks as the knife moves through it because of the thickness of the blade, rather than being cleanly sliced. Thinning a blade reduces wedging.

To give one example, lasers tend to be very thin with a flat profile: this eliminates wedging, but typically increases stiction.


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## Geo87 (Apr 29, 2015)

I always thought wedging was when a thick behind the edge knife gets stuck in a dense item, the product presses on the thick knife somewhere above the edge and acts like superglue, your knife comes to a complete standstill and is wedged / stuck in dense food. 

I've heard others describe it this way also.

Although your description of wedging /splitting food apart makes sense also


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## mark76 (Apr 29, 2015)

Rayuela said:


> Stiction describes the propensity of foods to stick to your knife when cutting, though it is a property of the knife, not the foodstuff.



Well, almost. I hope I use the right words, since English is not my first language.

Stiction is not the same as stickiness. Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact. (Wikipedia) We speak of stickiness when something has the tendency to have things stick to it. (Merriam Webster)

So when a knife gets stuck in, say, an onion, and you need some force to get it moving again (and this getting stuck is not due to wedging), we speak of stiction. When a potatoe slice gets stuck to your blade, we speak of stickiness.

Stiction and stickiness are properties of both the knife and the food.


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## Rayuela (Apr 29, 2015)

My bad about the stiction. I hadn't realised it was a technical term. I thought it was just a fun portmanteau word.


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## maiko (Apr 30, 2015)

Thanks for this clarification. These terms do seem to be used interchangeably, right or not.


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## daveb (Apr 30, 2015)

Ray's first post was closest to the terms as used in the knife world - at least this part of the knife world.

@ Mark - You could get a few buddies together and change the Wikipedia definition of sticktion to propensity of the knife to stick to the ceiling when thrown upward. :cool2:This would not change how it's used here.

Sticktion is a function of the knife, primarily the geometry and to a lesser extent the finish. Usually expressed as good food release (low sticktion) or poor food release (high sticktion). It becomes a factor in cutting when the user has to keep clearing product off the blade to continue cutting.


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## Chuckles (May 1, 2015)

@ mark76 - your English is far better than mine. No need to qualify your statements!

I now want to send my son to the Netherlands for school so he can be taught how to use English properly!


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## MrOli (May 1, 2015)

Wedging with a thick blade happens with coarse cuts, if you slice a carrot very thin then the wedge monster often becomes your friend with excellent separation while the laser can be the guilty of stiction...different tools for different tasks! Potatoes are interesting, their hard and wet nature can cause wedging and stiction. My favourite type of blade for these would be textured and reasonably thin.


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## XooMG (May 1, 2015)

When folks use the word stiction here, they're not simply talking about simple static friction, but about an effect that some call "wringing". Two precise surfaces are pressed together and lock together. The term "stiction" is used to descibe that, perhaps informally, in several fields. The mechanism seems to vary from basic vacuum pressure to liquid surface tension to molecular contact bonding.

A similar effect is found when lapping a stone with a diamond plate or other stone...when the surfaces conform closely, they stick together.


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## mark76 (May 1, 2015)

Hahah guys! Thanks for the compliments about my English.

The reason I happen to know a little bit about these words is that Ive been in lengthy discussions on the role of stiction in stropping. Ive written a couple of blog posts on this topic as well. Here is one of them: https://moleculepolishing.wordpress...-diamond-pastes-what-the-heck-are-they-doing/

This is a great topic and the jury is still out on what is happening exactly. Discussions are on-going on the Wicked Edge forum,the place to be for the most nitty-gritty sharpeners.


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## chinacats (May 1, 2015)

mark76 said:


> Discussions are on-going on the Wicked Edge forum, the place to be for the most nitty-gritty sharpeners.



??? May have to translate what a nitty-gritty sharpener is if they're hanging out talking about wicked edge...


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## mark76 (May 1, 2015)

Uh, chinacats, I know you longer by now, so perhaps this isn't the best place to discuss this. But if you want the best discussions on sharpening and a scientific approach to it, you should join the Wicked Edge forum. This forum attracts people interested in the best way to sharpen knives, not just how you do it with the Wicked Edge.


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## chinacats (May 1, 2015)

mark76 said:


> Uh, chinacats, I know you longer by now, so perhaps this isn't the best place to discuss this. But if you want the best discussions on sharpening and a scientific approach to it, you should join the Wicked Edge forum. This forum attracts people interested in the best way to sharpen knives, not just how you do it with the Wicked Edge.



Thanks, it must be the name that drives me nuts...you really think those people have sharper knives than the members here?


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## Pensacola Tiger (May 1, 2015)

chinacats said:


> Thanks, it must be the name that drives me nuts...you really think those people have sharper knives than the members here?



Some do, some don't.


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## Cadillac J (May 2, 2015)

Why is everyone getting into all these semantics...its all about foods suctioning to the blade, that is it.

Don't even remember anyone talking about "stiction" until a few years ago.


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## XooMG (May 2, 2015)

I guess two pages of replies isn't too bad before running into hostility.


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