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Is it possible

Wed Mar 27, 2013 4:52 am

Is it possible for a german knife like wustof to be as sharp or sharper than a similar priced japanese knife of similar type? Will it retain its edge better over a period of time? Just curious of your thoughts? Are all german and japanese created of equal sharpness?

Re: Is it possible

Wed Mar 27, 2013 1:22 pm

Jason

I think you are confusing 'sharp' with a fine edge angle. Just what are you trying to achieve with a Wusthof?

Re: Is it possible

Wed Mar 27, 2013 2:01 pm

A softer knife will not take a steep edge, but they can take a refined edge. This has nothing to do with stainless or carbon, hardness alone will give you the ability to take a steep edge. Alloys like Tungsten can help this also.

The more chromium a knife has, the less refined of an edge it can take because of carbide growth. Generally, chromium carbides are big. You can hit a sweet-spot of chromium to carbon, and AEB-L is the best example, as well as 440B, but chromium will also cause a knife to get chippy if you take the hardness above 59 or so because the carbides continue to grow the longer the steel soaks at critical temp while being treated. This is where powdered metals really shine.

Almost every single Wusthof and Henckel is made from NON-powdered, high-chromium stainless, meaning it has to be soft in order not to chip, not to mention the carbides are fairly large. Hence why you can't take most German knives past 2,000 grit or 15 degrees.

Japanese knives, on the other hand, tend to be made from carbon steel with little-to-no chromium, allowing the grain to remain fine and toughness to remain even at higher hardness. (aka 61+). Also, it seems more Japanese knives use powdered metal when they do use stainless, which is why even most stainless Japanese knives are harder than their European counterparts.

Super high-purity non-powdered stainless-steel can also be hardened extra points without becoming chippy. We just tend to call those steels "Swedish." :mrgreen:

Re: Is it possible

Wed Mar 27, 2013 7:31 pm

Where is a good resource to learn the chemical compositions of the various knife steels? It seems that it would be helpful for me to understand more of the chemistry behind the steels...

Re: Is it possible

Wed Mar 27, 2013 10:32 pm

[quote="jasonkierce"]Where is a good resource to learn the chemical compositions of the various knife steels? It seems that it would be helpful for me to understand more of the chemistry behind the steels...[/quote]

http://zknives.com/knives/steels/index.shtml

The database is also available for iPhones and Android phones.

Re: Is it possible

Wed Mar 27, 2013 10:56 pm

jasonkierce wrote:Where is a good resource to learn the chemical compositions of the various knife steels? It seems that it would be helpful for me to understand more of the chemistry behind the steels...


Chemistry is only part of the story - heat-treat is critical. You can have all the ingredients right in a cake mix but if you don't cook it properly...............

Re: Is it possible

Wed Mar 27, 2013 11:02 pm

Knife Fanatic wrote:A softer knife will not take a steep edge, but they can take a refined edge. This has nothing to do with stainless or carbon, hardness alone will give you the ability to take a steep edge. Alloys like Tungsten can help this also.

The more chromium a knife has, the less refined of an edge it can take because of carbide growth. Generally, chromium carbides are big. You can hit a sweet-spot of chromium to carbon, and AEB-L is the best example, as well as 440B, but chromium will also cause a knife to get chippy if you take the hardness above 59 or so because the carbides continue to grow the longer the steel soaks at critical temp while being treated. This is where powdered metals really shine.

Almost every single Wusthof and Henckel is made from NON-powdered, high-chromium stainless, meaning it has to be soft in order not to chip, not to mention the carbides are fairly large. Hence why you can't take most German knives past 2,000 grit or 15 degrees.

Japanese knives, on the other hand, tend to be made from carbon steel with little-to-no chromium, allowing the grain to remain fine and toughness to remain even at higher hardness. (aka 61+). Also, it seems more Japanese knives use powdered metal when they do use stainless, which is why even most stainless Japanese knives are harder than their European counterparts.

Super high-purity non-stainless steel can also be hardened extra points without becoming chippy. We just tend to call those steels "Swedish." :mrgreen:


Very nice explanation.

Should this become a sticky?

Re: Is it possible

Wed Mar 27, 2013 11:37 pm

Chemistry is only part of the story - heat-treat is critical. You can have all the ingredients right in a cake mix but if you don't cook it properly...............

Although not currently in place, Gator also has a heat treat section in the works. It should be pretty cool if he can get it to work. The zknives app is a great tool.

Re: Is it possible

Thu Mar 28, 2013 1:40 am

Woops, I had to edit the last part there. High-purity, "non-powdered" stainless, such as 13c26 and 19c27 can both be hardened past 60 without becoming chippy. Those talented Swedes.... :ugeek:

Also, 154CM can be taken up to 60 and 61 without becoming too chippy. Now, take it to 61-62 Rc and 10 degrees at the edge... things can start falling apart during use, whereas CPM154 will still hold up fine.

Re: Is it possible

Sat Mar 30, 2013 11:57 am

Brillant response Shaun, thank you for that.
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