About rust
Rust, oxidation, is the unique characteristic of our knives.
The surface of our knives will be oxidized by some reasons. Oxidation changes the color of the surface.
This oxidization can be removed by Rust remover easily.
Rust is not harmful for our health.
Why our knives get oxidize?
Materials of our knives are Hagane (carbon steel) and iron. Most of other knives are made by 100% stainless steel. Old time, stainless steel are not hard enough to make knife. Technology solved that problem. Some stainless are same hardness with Hagane (carbon steel), and it doesn't get rust. It's convenient materials.
Why we use Hagane (carbon steel)?
1. Cutting feeling
Because cutting feel are different from high-tech materials. The difference is not obvious. It's a bit. Some people feel it, some don't.
2. Easy sharpening
If you sharpen your knives by stones, you can see the difference between Hagane knife and newer materials. The difference is not obvious either. It's a bit. Some people feel it, some don't.
3. Feeling precious
I feel preciousness from Hagane knives even the low price one. It cannot be explained by word.
All 3 reasons are small thing and subjective. Only some people feel it, majority of people don't.
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Conclusions:
Our knives get rust. It doesn't harm our health. It can be removed by rust remover.
If you want to prevent oxidation perfectly, apply oil after washing.