Making a katana includes sever steps, such as preparation of raw materials, forging the raw steel into workable blocks, configuring the inner core structure of a sword, drawing out the steel block to the blade length, heating and hammering to make the final shape of the sword, straightening and flattening the blade, applying clay and heating to create the Hamon on the blade, correcting warps and bends, carving grooves and engravings.