The ideal kitchen knife

[Ethan P.]

So I've been making a kitchen knife for my lady, and I started picking up some things that I want out of such a knife. I originally forged it way too wide, and even after making it shaving sharp, the edge geometry made it nearly impossible to dice an onion or slice a potato. That being said, I also wanted something with a "hardier" construction because I didn't know what kind of cutting job she'd get herself into and I wouldn't want the edge to chip or something like that. I've settled on a knife that's about a quarter inch thick with a high flat grind and it's now passable for the things I ask of it. What this thread is about is tests to put a kitchen knife through to see if everything is in proportion.

 

So far I have made modifications based on:

Dicing an onion (the more lines/tinier squares the better)

Cutting a potato (both slicing thin disks and slicing through a thick part without splitting it)

Peeling and cutting an apple (same as the potato)

 

Though those are all better handled with a thin knife, I wanted it to be thick enough in case it needed to spatchcock (take out the spine and split open) a chicken. I just haven't had any handy.

 

What are some other good diagnostic tests for a new kitchen knife?

 

-Ethan

[Geoff Keyes]

Partly I think you've hit upon the key problem with knife design. No one blade will do everything. In my kitchen, which sucks BTW, I can never find the "right" knife, so I end up using whichever one comes to hand. There are two things that I find a basic chefs knife won't do. 1) The fine work a paring knife does best, and 2) the heavy chopping a cleaver does best. Everything else I do with a 10 inch chef, and a cheap one at that, the cobblers children, you know.

 

Geoff

[MichaelBrauer]

I beleive an experimental gator gutting is in order?

 

Ask her what she likes in a knife. My sister is a chef, and everyone has their particular preferences.

 

Cheers

[Orien M]

I make a lot of kitchen-type knives...I find them a fun challenge. Being usually fairly large, but thin, blades, they are "fun" to HT, and tend to warp unless well-normalized. I found 1/4" too thick for most uses, even with a heavy distal taper, so nowadays I'm tending toward less than 3/16" at the base of the spine. Length is a matter of opinion, but most people seem to prefer 8-10" (I myself like about a 5" long blade, though). Another pretty key design quality for kitchen knives (except paring knives) is that they be wide enough to keep the user's knuckles up off the cutting board.

 

Cutting tests are pretty informative; some food items will be cut by just about any geometry, but others want something more specific to work well (winter squash, for example, are hard to cut with anything but the thinnest and sharpest of blades, or a machete!). I do a lot of cutting tests anyway, usually working from soft stuff like meat and tomatoes, on up to cutting wood or antler/bone...the more materials you try to cut, the better idea you'll have what your knife is capable of.

 

Different chefs have different knife styles, and tend to prefer different shapes depending on their technique. To oversimplify, there tend to be "slicers" and "rockers"...those who rock the knife a lot tend to like more belly. I've actually been meaning to poll people, on cooking forums and the like, "what do you like in a cooking knife", and see what kind of recommendations I get. I may take some knives around to local chefs for testing, too.

Edited December 15, 2010 by Orien M

[alexb]

My wife says..............thinner.

No matter how thin it is,I think she's looking for see- through myself.

 

So I made her a couple under 1/16 for veggies and a couple at around 1/8 for meat and such.

 

I had a dickens of a time with warp on the thin ones,a thin claycoat with solid normalizations really helped with that.

[jake cleland]

i generally keep kitchen knives between 1.5mm and 2mm. extra thickness provides stiffness and mass, but doesn't add much in terms of 'strength'. if you have to cut through heavy bone, then use a saw, but a properly heat treated blade should handle a chicken no bother - i regularly butcher rabbits with a 2.5mm blade, and it doesnt blink at removing the feet and head.

[Dick Sexstone]

Google Dave Martell....

 

He did a lecture on chefs knives at Ashokan last year that was one of the best lectures I've heard there.... read everything he has to say... his info was invaluable...

 

Dick

[Peter T. Swarz-Burt]

To add to what has already been said...

 

In kitchen knives, it is pretty much true that thinner is better. Remember, the thickness at the spine will have zero effect on whether the edge chips out, and in reality a thin edge is far more likely to flex than to chip. If you are worried about chipping, then temper back a little further or use a tougher steel; it is better to re-sharpen a bit more often than to have a chipped edge. I believe some makers do an edge deflection test by pressing a brass rod against the side of the cutting edge; if it flexes and returns then you are in good shape... chipping or bending count as failure. I would also agree with the statement that no single knife will handle every job, so attempting to achieve that will just lead to frustration.

 

All of my favorite kitchen knives, regardless of length, are 1/16" and under at the spine. Those that cut best also have a minimal or non-existent edge bevel... the knives are ground thin enough that the main bevel almost meet. A thicker edge like those seen on most hunting knives (by this I mean that the edge bevel is easily visible), will do fine for the slicing of soft materials but fails utterly when attempting to cut harder items like carrots (I prefer the carrot test over the potato test). The thicker edge tends to crack the item being cut and the process requires far more effort than it should. This is a dangerous situation because you are not only putting extra effort into the cut, but you also have less control over where the knife is going. A thick spine will have a similar effect, but I have definitely found that the edge thickness is the most important factor. Having said this, I see no reason to make any general use kitchen knife thicker than 1/8" at the spine, and most can be much thinner. I found that looking at production kitchen knives helped a lot in figuring out what cross-sections and designs worked best. After all, these companies have been researching this for a very long time.

 

I think the trickier part is actually making this cross-section without, as has been mentioned before, undue warpage. Here are a few suggestions of techniques that I have either used myself or have heard about over the years:

 

-harden first, grind later... this definitely helps with warpage, but you have to be VERY careful about over-heating the edge as you get close... many folks who specialize in kitchen knives have water cooled grinders.

-use an air-hardening steel such as L6 (air hardens beautifully in thin sections), since these are far less prone to warpage in the "quench".

-preheat the blades in a toaster oven prior to heating to critical in a forge or saltpot. I have found that my worst warping issues arise from the edge heating so much faster than the spine. At one point I thought that a "rippled" edge was the result of the quench, but I have since discovered that it actually appears in the heating. By pre-heating to 600F or so in a toaster oven, I have been able to pretty much remove this issue. If you are HT'ing using an electric kiln of some kind, then put the knives in while the kiln is still cold so they can heat evenly and slowly.

 

Peter

[Jóhann]

 

This is one of the best knives I have ever used in a Kitchen.

I used to work at a professional kitchen and this knife was incredible it has a thin edge, and feels really good in the hand.

Unfortunately it was destroyed when the hotel I worked at burned down.

But all in all this is everything I look for in a kitchen knife.

[Howard Clark]

The best kitchen knives I have made are all very thin. One of them is only 1mm at the spine, and it is flat ground all the way from there to the edge which was only left about .25mm when it was heat treated (which had to be done more than once to get it flat and right). The first time I hardened that blade, I was newly excited about using PEO/water for quenching, and it came out like a giant potato chip, warped in about every possible direction. Used high temp. salt to heat it up and straighten it out, then quenched in low temp salt and pressed it flat between heavy plates the next time. Came out much nicer that way.

 

Thin, thin, thin. Knives always cut better when they are thin. Flex better too.

[Ethan P.]

Yeah, in fact, the knife that I use in the kitchen is super thin (from a lawnmower blade) and slices like nothing. I've gotten her knife now to a point where it will pass the brass rod test (the edge flex test) by a full flat grind, which I'm pretty sure thinned it out a little bit too. As far as personal preferences, she doesn't really have any since I'm the one teaching her how to cook. I modelled this knife after mine (but thicker). I think what was throwing me off was a book on Japanese kitchen knives that my college's art library has. It has scans of blades and their spines, and the knife they use to butcher fat (round) fish is THICK. It's single bevel, with a short bevel on one side and flat ground on the other. Then again, they also have some very thin blades.

 

I'm glad to see where this thread is going.

 

-Ethan

[Bob Ouellette]

I just finished my first chef's knife not too long ago. The biggest problem I had was the blade drooping in the forge. It didn't really have the integrity to hold it's shape once it got hot. I solved the problem by sticking a piece of iron in the forge that will support the blade with the spine down and the edge up. As long as it's not laying flat, it does ok.

Edited January 25, 2011 by Bob Ouellette

[Beau Erwin]

Just resharpened a yanagi I'd made a while back. I really need to pop the handle off and give it another tempering cycle at around 400.

It was my first one to do, and the grind ended up going to high. The damn thing is sharp as hell, but the edge can be a little chippy. I figure tempering it a bit further would fix that as I'd left it kinda hard being a japanese style.

 

I'm enjoying that santoku I'd made tho. It had a spine at 2mm. the bevel goes up about 1/4 of the width. I bet it'd slice even better if I took it up about a third. I'm enjoying trying various japanese styles.

 

The japanese use the Deba to fillet and cut up meat near bones as the thinner knives would chip out due to their hardness.

 

Has anyone tried use Cruforge V as the core in a japanese style knife?

[ryanwrath]

AH this is a question i have as an owner of a couple of Global kitchen blades (Pictured above).........how did they make the handle? it feels like hollow metal, and seems very integral to the blade, i thought many times it would be badass to be able to do it, but i have no idea how to actually make a blown up handle like that.......or maybe its wood cored or somehting i have no idea.....any questions or youtube videos? hehe thanks

[Antoine]

 

 

Has anyone tried use Cruforge V as the core in a japanese style knife?

I think Sam made one ....

 

Antoine

[P.Abrera]

Speaking from theory rather than actual experience here...I think the thick-spined japanese knives work well cause of their chisel grind. Flat side pulls the edge into whatever you're cutting and the beveled side pushes the sliced material away. A thick-spined V-grind just wont work as well. Otherwise thin is best for the kitchen in my experience with the more "usual" kitchen knives.