Seki Kanetsugu Zuiun Santoku 18 cm. The Zuiun is a special model manufactured to celebrate the company's centennial. Seki Kanetsugu Zuiun knives have blades with a wavy “hamon” pattern similar to Japanese swords. In its current incarnation, Seki Kanetsugu Cutlery has been making modern blades that realize the characteristics of Japanese swords--unbreakable, unbending and very sharp. The company also infused the Zuiun with the spirit of such swords. The blade is made of Damascus steel that uses powdered stainless steel SPG2 for the core material. Finely sharpened by artisans, the surface of the blade features a scudding cloud-like pattern. It is also forged into a V-shaped "hamaguri-ba" clam blade, reflecting a characteristic of Japanese swords.