These knives are forged by Suogo Yamatsuka in Sakai, Osaka from Ginsan-ko (Silver #3) steel and are rust and stain resistant. Ginsan-ko steel has 13% chromium and high carbon content which allows for easy maintenance and great cutting performance. They take a great edge and are easy to sharpen and maintain. The blades have a single bevel and are all hand sharpened. All craftsmen involved in making these knives are certified Sakai knife makers called Dento Kougeishi. The spine and heel of each knife is rounded and mirror polished.