Question about Konosuke HD

[mpjunior]

So I got a 270mm Konosuke HD.
first of all wow, this knife is something else!!!

there is one thing im dont understand, I used it to chop some carrots and the blade stained orange (not that i really mind), is that supposed to happen?
mark

 

[GLC]

Carrots are notorious for staining. You'll notice Konosuke calls the metal "semi-stainless" steel. That's a good thing, generally. It means it could be tempered so as to hold an edge well. I suspect that's the same as saying high-carbon stain resistant steel. You may see staining with carrots, food colorings, and highly colored things like mustard and paprika, not that the knife will see most of those in normal use. Carrots will also stain ceramic knives. The only thing you might want to try is to wipe it immediately after cutting carrots or anything else that appears to stain. You can also try to clean it with a non-abrasive, like Bartender's Friend or just baking soda. Some tools bear honorable wounds from their work. I'd consider this one of them, if I liked the knives.

Carrot stained ceramic knife. Slight permanent stain remains after cleaning.

 

[Rob Babcock]

The HD is semi-stainless. Certain things will stain more than others. Fresh basil will sometimes stain even "stainless" steels. I'm a bit surprised that a carrot stained it- did you leave it wet for a long time?

The stain is called "patina" and is harmless. You're got yourself a very, very good knife! Konosuke makes some of the best.

 

[taxlady]

In other languages it isn't called stainless. In the Germanic languages it is "rust free" and in the Latin languages it's non-oxidizable.

 

[mpjunior]

Thanks for the replies!

Rob- of course you love this knife i got it on your reccomendation a few months ago
Also got myself a edge pro chosera kit, a tojiro bread knife, and an HD petty what can i say, its been fun lately

The HD is semi-stainless. Certain things will stain more than others. Fresh basil will sometimes stain even "stainless" steels. I'm a bit surprised that a carrot stained it- did you leave it wet for a long time?

The stain is called "patina" and is harmless. You're got yourself a very, very good knife! Konosuke makes some of the best.

 

[Rob Babcock]

Those Choceras are the bomb! I'm glad my advice was useful. Mark has a new Konosuke model now that uses the "mystery steel" of the HD but the general shape & profile of the Masamoto KS. I'm really drooling over that one...

 

[Rob Babcock]

In other languages it isn't called stainless. In the Germanic languages it is "rust free" and in the Latin languages it's non-oxidizable.

In reality the idea of a "stainless" or non-oxydizing steel is a myth. All steels will rust, SS just rusts less. The generally accepted definition of stainless is that it contains 13% or more Chromium. That's the element that impedes rust. At the opposite end you have steels like Shirogami which are just carbon added to the purest obtainable iron. There are traces of sulphur and other impurities but no Chromium, molydenum, vanadium, tungsten, etc.

You can toss a typical SS knife in a bucket of strong bleach water and it will begin to oxidize pretty quickly.