How long a Nihonto last?

[Dereks]

Hi,

 

Might sound silly but i have a question. Do you know how long steel(tamahagane) would last with proper care? I know there are blades from 11th-12th century which have been taken care of properly but do you think they will last another 1000 years with care? What about the integrity of the steel? Do you think the steel weakens with time? 

 

Let me ask you like this, do you think a 13th-14th century sword would be broken if you try to cut bamboo with it?(of course i have no intention to do this)

 

 

 

 

[John C]

Derek:

Not sure if this helps, but remember there was a dagger found in King Tut's tomb made (supposedly) of meteorite steel. That was placed there around 1324 B.C., if that gives any indication. 

 

John C.

 

 

[Tensho]

Indefinitely.  Depending on if its taken care of, and hasn't gone through a plethora of polishes. 

 

Loaded question, not all are created equal. It takes skill to cut without damaging the blade. Bending is fairly common as well. Lots of older references of nihonto "breaking" by ridiculous means. 

[Dave R]

Long enough that the question will not arise in our lifetimes..... Barring abuse and neglect of course.

[OceanoNox]

If you avoid oxidation and damage in general, the blade will stay as it is. However, carbon can diffuse even at room temperature, so given enough time, the behaviour of the steel might become different.

[drbvac]

Good question but as stated - if cared for - how long is a rope?

[Rivkin]

There has been modeling suggestion that martensite is stable over about 500 years, but the authors modeled a very small volume... it is expected that a larger sample will be more stable.

So the metallic structure likely does not dissolve by itself unless its about 5-10,000 years.