Katsuko Tanaka is the principal blacksmith at Tanaka Kama Kogyo, a famed shop in the town of Matsubara in the city of Omura, Nagasaki Prefecture. They have their origins in a blacksmithing tradition that came to the town with refugees from the Battle of Dannoura, over 800 years ago.
Tanaka-san hand forges all of these fine blades out of the very popular Aogami 2 steel as his core component. He hardens the steel to a Rockwell rating of 62HRC, which is a sweet spot for Blue #2. He then forge-welds a layer of soft stainless steel to the core using the san-mai method of awasi (cladding). The soft stainless steel not only protects the inner core of Aogami 2 steel, but also adds a level of dampening to the blade which reduces the chances of fractures while making the blade easier to maintain.
Even though the cladding is stainless, these knives should be kept clean and dry to avoid corrosion to the exposed core steel. The cladding receives a really lovely nashiji, or pear skin, finish. This not only enhances the visual appeal of the knife but offers a huge amount of protection to the otherwise corrosion-prone inner core. This particular knife comes with a very nice custom octagonal handle pictured.
Blacksmith: Mr. Tanaka
Construction: Hammer Forged, San Mai
Cladding: Nashiji Stainless
Edge Steel: Blue #2
Edge Grind: Even
Weight: 7.6 ounces / 216g
Blade Length: 190mm
Spine Thickness at Base: 3.5mm
Blade Height: 79mm
Handle: Rosewood Octagonal
Ferrule: Black Pakkawood
Please note, Mr. Tanaka puts a notch in the tang and this is done on purpose and is not an installation mistake.