Ceramic knives

[toytoy]

http://www.ceramicknife.org/

These ceramic folding knives seem to be great and quite inexpensive. These ceramic knives are said to contain a certain amount of metal powder to trigger metal detectors. Does this process reduce the strength of the blade?

[Spoonrobot]

Aren't the handles steel enough to set off a metal detector?

As a general use knife I don't really like ceramics as a blade material. I have yet to see any real advantages over high-end modern steels. If you end up getting any, let me know how you like them. Always interesting to hear about new technology.

That and those designs are ugly!   

[Benner]

Wouldn't a ceramic knife easily shatter if dropped or if it was bent or twisted?

[hawkchucker]

Wouldn't a ceramic knife easily shatter if dropped or if it was bent or twisted?

Yes they will, however for a knife you cannot use on frozen  food, and on bones. It will stay sharp very long.

[Spoonrobot]

It was my understanding that ceramics do not handle shock very well but the FAQ page states that these knives won't shatter if dropped because the Zirconium oxide "is very strong." (But will chip on bone? Also stated in the FAQ.)

This site sounds kinda fishy, it states that the ceramic material is more costly to produce and finish. Then why are the knives on @30$?

Super ceramics?

[hawkchucker]

Kyocera has a great Ceramic knife. I have used thier 6 inch chefs and it was a fantastic cutter, but the salesman stated that it would void the warrenty to chop, Cut frozen food  or to even be used to bone any meat, Use on a Phenomic or glass cutting board. So I find it interesting it would survive a fall.

After looking at this.http://www.metrokitchen.com/about_kyocera I stand corrected it will not shatter, but will break. They msut have made some inprovements to the product. It does work well and will stay sharp a long time, but read up on it. There is a lot It cant do.

[toytoy]

I think the blade's shape may affect a ceramic knife's strength.

If you make a solid ZrO2 brick, you may never break it. A large and thick piece of ceramic is strong.

If you make a very large and thin knife, you may shatter it.

The strength of a ceramic knife may be determined by its shape.

[FredKJ]

Ceramic is certainly a good blade alternative and must have it's uses.  Personally I haven't yet found an advantage for my uses over conventional steel knives.  Yes they are more brittle but if taken care of and used properly should not be a problem.  They are generally far more expensive.  While they hold a very sharp edge they also cannot be resharpened by the typical user.  To spend around $100-$200 for a knife to chop veggies instead of an inexpensive $15 knife it's hard to make a business case.  The typical inexpensive cooking knife is around a Rc 54.  This is pretty soft and yes needs sharpening.  But I'd rather sharpen occasionally than spend big bucks.  To compare a folding knife like that against my good ol' Buck lockblade it's also hard to see the advantage.  It is less likely to break and I can resharpen it.  Still if you want to pay the bucks for a ceramic they do work well.  Understand that when they do actually get dull they have to be professionally sharpened. 

[CQC-7]

It is interesting that this thread showed up.  I was going to order a ceramic folding knife but I have my opinions on them that are not necessarily from experience I might have to buy one just to test it.  Having been an archaeologist I have a lot of experience with stone blades which share many of the properties of ceramics.  I know 3 things about stone blades 1. they break and 2. they dont break as easily as you think and 3. They are very very sharp or they are very very broken.  I can see #1 and #2 being true of a ceramic blade but #3 I dont know.  Stone chips off and distorts the edge geometry and makes it seem dull but it is actually still a sharp edge but at a different angle making it harder to cut anything.  I dont know how ceramic gets dull because if it is anything like stone it would have smaller microfractures along the cutting edge I really cannot see the blade wearing with a rockwell hardness that is nearly off the charts.   

[Grant Lamontagne]

I bought a ceramic kitchen knife from Boker a few years ago and it cuts like a laser beam and is still sharp every time I visit her which is about every year or two.  My father keeps his hunting knives sharp but rarely does the kitchen knives, and it was always my job to sharpen them when I visited!

As a kitchen knife, under controlled conditions I'd say ceramic is about the absolute best material for a knife.  As a folding multipurpose blade though, I have my doubts.  If dropped it could shatter, and it will leave you with a handle and a large hole in your wallet.  I think steel functions well enough for day to day use and still provides resistance to what I like to call "The Universe At Large."  Sure, ceramic holds a better edge and is impervious to corrosion, but it isn't shock or impact resistant.  You may bend the tip of a steel blade but it's still usable.

That having been said, it reminds me of an interesting story about Kevin "Mad Dog" McClung, owner of Mad Dog Knives and one of the pioneers of mainstream ceramic knives.  He was being interviewed in a restaurant one day about his new line of ceramics when the waiter interrupted and asked what the point was of a ceramic knife?  Ceramic can't cut anything....  Mad Dog's only reply was to pick up a fork and start whittling away pieces of stainless steel with the ceramic blade!

I can only imagine the look on the waiter's face!

Def

[FredKJ]

It is interesting that this thread showed up.  I was going to order a ceramic folding knife but I have my opinions on them that are not necessarily from experience I might have to buy one just to test it.  Having been an archaeologist I have a lot of experience with stone blades which share many of the properties of ceramics.  I know 3 things about stone blades 1. they break and 2. they dont break as easily as you think and 3. They are very very sharp or they are very very broken.  I can see #1 and #2 being true of a ceramic blade but #3 I dont know.  Stone chips off and distorts the edge geometry and makes it seem dull but it is actually still a sharp edge but at a different angle making it harder to cut anything.  I dont know how ceramic gets dull because if it is anything like stone it would have smaller microfractures along the cutting edge I really cannot see the blade wearing with a rockwell hardness that is nearly off the charts.   

Interesting.  I have studied flint knapping as well.  Ceramics do seem to have similiar qualities but I don't think they fracture the same.  Some of the sharpest blades you can have are flint knapped.  In fact today they are often used in the high-tech realm of microsurgery for that very reason.  They are so sharp.  I have looked into getting some flint knapped knives.  They're kind of nice.  Have similiar characteristics to ceramic.  Done right they can be sharper than steel knives.  Of course breaking and fracturing is an issue.

[CQC-7]

It is interesting that this thread showed up.  I was going to order a ceramic folding knife but I have my opinions on them that are not necessarily from experience I might have to buy one just to test it.  Having been an archaeologist I have a lot of experience with stone blades which share many of the properties of ceramics.  I know 3 things about stone blades 1. they break and 2. they dont break as easily as you think and 3. They are very very sharp or they are very very broken.  I can see #1 and #2 being true of a ceramic blade but #3 I dont know.  Stone chips off and distorts the edge geometry and makes it seem dull but it is actually still a sharp edge but at a different angle making it harder to cut anything.  I dont know how ceramic gets dull because if it is anything like stone it would have smaller microfractures along the cutting edge I really cannot see the blade wearing with a rockwell hardness that is nearly off the charts.   

Interesting.  I have studied flint knapping as well.  Ceramics do seem to have similiar qualities but I don't think they fracture the same.  Some of the sharpest blades you can have are flint knapped.  In fact today they are often used in the high-tech realm of microsurgery for that very reason.  They are so sharp.  I have looked into getting some flint knapped knives.  They're kind of nice.  Have similiar characteristics to ceramic.  Done right they can be sharper than steel knives.  Of course breaking and fracturing is an issue.

I dont think that they would fracture the same but they would certainly break if dropped and they landed a certain way.  I believe that Mr. Crabtree had his heart surgery done with blades that he knapped.   

[hawkchucker]

Def
How does the Boker stand up againt the Kyocera.?  Have ya tried both? I dont know much about the Boker and they do interest me but I know nothing about them.

I know that the Kyocera cannot go anywhere next to a dishwasher. I dont know if that has anything to do with the blade compound that they use ( I know that there Ingredients are closely guarded) or the handle material.

Also what cutting board have ya been using? I know we were told no Plastic phomamic or glass, and that is really all we can use in the resturant.

[Grant Lamontagne]

I can't honestly say- I've never had/used any other ceramic blades than the Boker.  I used it for some time before giving it to my mother and I enjoyed it.  I usually use a wood or plastic cutting board at home, and I found that a cutting board is indeed necessary or it'll make a nice mark in your counter top.  Ask me how I know this!

Def

[FredKJ]

I'd never put any of my sharp kitchen knives in a dishwasher anyway.  That's a good way to dull them.  For fine kitchen slicing I can see where a ceramic knife would work well.  It's hard to see it for any outdoor or utility purpose.  There are other high end options such as forged liquid or powdered metal that have very good qualities.  Even being careful at some time you will probably put some prying force on a utility type knife.  That's a total nono for a ceramic.

[CQC-7]

I dont know if there is any truth to this but I guess that if a sharp knife is used it is less likely to damage vegetables and fruit and makes the food taste better.

[bobofish]

On that note, ceramic kitchen knives were first envisioned for prep cooking in restaurant kitchens. When you have to dice 3 bags of onions for a service, every ounce of extra chopping pressure from a dulling knife really adds up over a shift.

[CQC-7]

I guess that it really would make a difference.  I remember when I worked in a larger kitchen our knives were so worn from constant sharpening that they literally looked nothing like their original shape.