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What to look for when buying knives (2007) (theatlantic.com)
26 points by Tomte 239 days ago | hide | past | web | favorite | 13 comments

Ugh - Carbon steel is not easy to sharpen because it is soft. It is because it contains fewer carbides. Typical stainless steel alloys used in production knives are hyper-eutectoid, and the excess carbon (anything > .77%) ends up forming carbides with the alloying elements. These carbides - Tungsten, Chromium, and Vandium carbides, are harder than the surrounding matrix of hardened and tempered steel, and can only really be "cut" with a diamond stone. If you only have a water stone, the high proportion of carbide in stainless knives makes it difficult to sharpen because the exposed bits of carbide in the matrix are harder than the stone and don't get removed.

Another issue with commercial knives altogether is that frequently the mass market ones are soft by design (<58 HRC). This saves costs in the post-heat treatment grinding into final form. (knife blanks are oversized when heat treated so that any slight warpage during quench/temper can be ground away). handmade knives are usually not done this way, and so many hand makers are comfortable going much harder since they are less worried about the economics of hard material removal at mass scale.

(Source: Have spent several years learning to make knives)

For good browsing, check out hypefreeblades.com

Pardon me if I use the wrong nomenclature or if this question is wrong in some fundamental way: Would the higher hardness of the carbides mean a high-carbide knife needs less frequent honing/sharpening when used in regular cooking tasks?

Carbides are a double edge sword. On the one hand they impart "wear resistance" but only if the heat treatment is done right (read: very precisely). Frequently, that is not how commercial stainless is done, though. On the other hand, they can make it harder to sharpen.

Usually, good heat treatment can lead to fine grain carbides, while bad heat treatment does not get the carbides into solution very well prior to quenching and they get too large. (This is not the same thing as grain growth). When they are big, they impart roughness to the edge and difficulty of sharpening with no benefits in wear resistance as the steel matrix around them wears away.

If you are interested in this, I can't recommend John Verhoeven's "metallurgy for bladesmiths" enough. It is a free PDF if you search for it. (If you like open source things, I recommend reading the foreword especially).

"Carbon steel is soft" - uh, most metal is probably going to be soft if it isn't heat treated, but carbon steel can become so brittle it shatters when you tap it.

And Damascus steel isn't particularly good. It's mainly an artsy gimmick. But that's not to say you can't still have a strong, sharp Damascus blade. The visual has nothing to do with how the knife performs.

He's right that you only need three knives: A large thick chef's knife, a smaller thin knife, and a generic serrated knife. None of these have to be good at all to cook with, but you will enjoy cooking more with purpose-made cutlery made of hard steel that you can simply re-hone to keep them working efficiently. A "good" stainless steel is often perfectly fine, but most often it will not stay as sharp as long.

But if you're new to culinary knives, you should not go out and buy good knives. You should buy a pack of a bunch of different looking shit knives for about $30-40, the heavier the better. Practice cooking with them. You will notice some knives are annoying with certain cutting techniques, and how your shit knives may actually be too shitty to practice certain techniques. Hopefully you will learn to take care of your knives, what kind of cutting surfaces to use, how to hone or sharpen them, etc so when you go to buy a good set, you get what you actually want to use.

After cooking with shit knives, you may learn you don't mind knives that can't cut a tomato without poking through the skin first and then slicing from the meaty part. But that's basically how you choose a knife - whether your knives are sharp or will stay sharp, whether they "feel right", how much you care about maintenance. If you don't care about any of this, use shit knives. If you are a dork like me, make your own knife.

If you do want a good knife but don't want to spend the money, learn about good manufacturers of older knives and look for some at a local flea market. You may only need to sharpen it or maybe put a new edge on it, both of which are easy once practiced. No need to spend $150 on a knife you can find online or in a flea market for $25.

> And Damascus steel isn't particularly good. It's mainly an artsy gimmick.

To add to this, most "Damascus steel" knives aren't made of folded steel in the core. The core is a solid piece of some metal and the exterior Damascusoid material, created by pattern welding, gets attached to the sides.

It's functionally pointless, but it does look really nice and shouldn't hurt the usefulness of your knife in any way. My EDC pocket knife is pattern welded for this reason.

If done right it does no harm, but crappy damascus is brittle and prone to oxidation, and will drastically shorten the life of an otherwise functional cheap knife. Best to avoid it unless for the bling factor on a quality manufacture knife, or replica.

Keeping knives sharp is 90% of the battle.

Knives stay sharp pretty easily, the trick is keeping the edge straight. Learn to use the stick that came with your crappy knife set and you will get a good year of daily use out of each sharpening. Additionally, keep your blade dry after cleaning to avoid pitting, which happens most rapidly on the edge.

This guy is clueless about metal alloys, and why they are, omitting the general shape, the most important quality of a 'good knife', followed closely by handle and balance. You can re-edge any knife, so talking about how you can finish a stamped steel blade just as well is missing the point, quite literally.

I want a knife that is made out of a really strong metal that holds its edge. I don't mind sharpening my knives. I just dislike sharpening them all the time.

What is the best type of steel or alloy for me?

I use ceramic knives for the very same reason. Guess it doesn't cut it for you if you insist on this: "made out of a really strong metal"

Ceramic knives are quite resistant to wear, but once worn you can essentially toss such a knife into a garbage can, that is how hard they are to sharpen. They also lack in toughness and are quite brittle so are unsuitable for some common tasks...

I had some ceramic knives, but they are too brittle, and once they lost their edge I was never able to get it back.

Are you telling me that there is no strong metal that comes close?

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