These knives are designed for Zwilling J.A. Henckels by certified Master Bladesmith, Bob Kramer, the only Master Bladesmith in the world specializing in kitchen cutlery. Each knife is handcrafted in Seki City, Japan to Bob's exact specifications. They feature the precise quality of carbon steel (51200 straight carbon steel*, heat treated to a hardness of 61 rockwell) that Bob chooses for his custom artisan knives. These knives are built for remarkable strength and unmatched edge retention. They also feature brass bolsters and handsome natural, triple rivetted, African blackwood handles.