Petty 135mm (5.3 in) Blue#2Type: Petty Finish: Kurouchi Damascus Blade Length: 135 mm (5. 3 in) Construction: Awase Core Edge Steel: Blue(Aogami)#2 HRC (Rockwell Hardness): 60 61 Handle: Walnut Bevel: Double Bevel Place of Origin: Tosa Blue (Aogami) #2 (Hitachi Metals Ltd.) is made by adding Chromium and Tungsten Wolfram to White Steel #1. This results in increased toughness and the production of hard carbide molecules, which improve edge retention. Many knife users have noted