All Casström knives are cryo-quenched. Cryogenic hardening is a treatment process where the steel is cooled to very cold temperatures with the use of nitrogen gas. This enhances the performance of the steel at a molecular level and in practical terms, gives the blade more wear resistance and is less prone to chipping compared to a blade with the same hardness that was not cryogenically quenched.
Uddeholm Sleipner steel is a new-generation D2 tool steel well suited for knife manufacture. Once hardened, Sleipner steel offers good edge retention and is easy to sharpen, even in the field. The addition of almost 8% chromium offers better stain resistance in comparison to other carbon steels (although it should be pointed out that it is not stainless steel, and is not resistant to staining or corrosion).
C 0.9%, Si 0.9%, Mn 0.5%, Cr 7.8%, Mo 2.50%, V 0.5% (average %)
Böhler Tool Steel K720 (O2) is a very tough and strong oil-hardened high-carbon tool steel. The focus of the steel is toughness and edge stability. The chemical composition allows it to be hardened to a high degree whilst maintaining ductility and toughness. This means the blade holds its edge for longer at the same time as it is resistant to chipping and cracking under heavy use. This steel also has a very fine structure making it easy to sharpen and achieve a razor-sharp edge with. Whilst easy to sharpen, the low chromium content means it will tarnish if left wet and it must therefore be wiped after use and protected by oil or wax when put away for storage if you want to avoid tarnish building up.
C. 0.9%, Si. 0.25%, Mn. 2.0%, Cr. 0.35% V. 0.1% (average %)
N690 is cobalt-enriched steel from Austrian steel company Böhler. N690 shares some properties with other cobalt-enriched steels, e.g. ATS-55 and VG-10. The cobalt increases the wear resistance of the blade thanks to the even crystal structure, allowing the blade to hold a good edge.
C 1.08%, Si 0.40%, Mn 0.40%, Cr 17.30%, Mo 1.10%, V 0.10%, Co 1.50% (average %)
Sandvik 12C27 is a very popular stainless steel for Scandinavian knives due to the combination of good edge performance (stability and ability to take an edge), high hardness, and good corrosion resistance. Blade re-sharpening is easy and edge stability in terms of microchipping and edge folding or rolling is also good.
C 0.60%, Si 0.40%, Mn 0.40%, P(max) 0.025%, S(max) 0.01%, Cr 13.5% (average %)
Sandvik 14c28n is the latest development in Sandvik's range of knife steels. Optimized chemistry provides top-grade knife steel with a unique combination of excellent edge performance (stability and ability to take an edge), high hardness, and good corrosion resistance. This new grade allows for better hardness and wear resistance to previous grades without affecting the microstructure. Blade re-sharpening is therefore easy. At the same time, edge stability in terms of microchipping and edge folding or rolling is also good.
C 0.62%, Si 0.20%, Mn 0.60%, P (max) 0.025%, S (max) 0.010%, Cr 14.00%, N 0.11% (average %)