Steel grade:

Sleipner steel allows the knife to stay very sharp, longer and even with very heavy use without crumbling to the extent often seen with stainless and high-alloy steels. Its chemical composition allows tempering to high hardness while maintaining ductility (ability to deform without breaking) and toughness, while still being relatively easy to sharpen and capable of achieving a very sharp and durable cut. Because of its 8% chromium content, it is resistant to corrosion to some extent compared to ordinary carbon steel (about 0.5% Cr), but not as good as stainless steel (13% Cr). Therefore, the knife should be dried after use and protected with oil or wax when stored in an environment with high humidity.

Sleipner steel belongs to the 8% chromium die steel category and is designed to have a toughness close to simple tool steel, such as A2, but with a much higher wear resistance, closer to D2. Casström adds a cryogenic treatment cycle at sub-zero temperatures with the use of liquid nitrogen after quenching to harden the blades and improve steel structure.
Composition: C 0.9% Si 0.9% Mn 0.5% Cr 7.8% Mo 2.5% V 0.5% (~HRC 60)