Opinel knife "Carbon" blade series are made using steels with a high carbon content, which is what makes it possible to achieve the excellent hardness after heat treatment, guaranteeing the good strength of the cutting edge, resistance to wear and easy sharpening.
Carbon has a low resistance to corrosion caused by moisture, which means that certain precautionary measures are necessary when using and storing the knives: we recommend that you avoid damp environments and that you dry and grease the blade after use.

The hardness obtained after heat treatment are theoretically slightly greater in steels that do not contain chrome. The cutting strength is therefore better with a “carbon” steel and sharpening of carbon steel blades is much easier than sharpening of stainless steel blades.

Left Photo: Opinel N^o8 Carbon steel lost at the golf course (4 months). Notice the pristine stainless steel safety ring next to the corroded carbon blade.

Opinel Sandvik 12c27-MOD Stainless steel (acier inox)

The addition of chrome very markedly increases resistance to corrosion caused by moisture. Steels are then called “stainless” and they can be used with fewer restrictions. The stainless steel capable of undergoing the heat treatment that gives it its good hardness is called martensitic. Sandvik12c27 MOD: All Opinel stainless steel blades are modified by adding at least 0.40% of carbon, giving it a good cutting edge but which explains why knife blades are not totally corrosion-proof. Only a carbon-free steel would be, but it would not have the hardness guaranteeing a good cutting quality and the excellent strength of the cutting edge.

The Opinel No8 Stainless Steel to the right has 5 components, weight 1.6 oz and is, in our opinion (and the one of millions) the best knife for the buck anywhere in the world for the past 120 years..