After getting four kinds of steel, Shingane (center metal), Munegane (back metal), Hanokane (blade metal) and Gawagane (side metal) by Shita-gitae (forging), the second Tsumi wakashi (stacked and heated metal) and Age-gitae (finishing forging), three layers of Munegane, Shingane and Hanokane are forged and welded, and struck and elongated to get four times the material, 20mm thick, 40mm wide, and 90mm long, and then cut into four. This is called the 'Core metal (芯金).' Gawagane is also heated, and struck and elongated to become twice as long as the Core metal, and is then cut in the center to make two Gawagane of the same length as the Core metal. Gawagane, Core metal and the other Gawagane are stacked in this order, heated, forged, and welded, then struck and elongated into a 15mm thick, 30mm wide, 500 to 600mm long plate. Teko' is cut off, then 'Nakago' which becomes the grip of a sword is heated, forged and welded.