Yoshikane's hand forged SKD series has 405 stainless steel cladding (jigane) with tsuchime hammer markings and a hard SKD tool steel core (higane) as the cutting edge. SKD was originally formulated for metal cutting applications. Hardened to 64 HRC, these knives hold a keen edge for a long time. They have a degree of toughness that allow them to be sharpened at a very low angle, making for very smooth cutting feel. Since they're forged with a wide, kiriba primary bevel, they also allow for easy thinning down the road. Considering the edge life and toughness, this steel sharpens with surprising ease. They are ideal for the professional or home cook who is looking for a great workhorse, long edge life, and easy sharpen-ability.