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.
下鍛えと2回目の積沸かし、上鍛えによって心金、棟金、刃金、側金の4種類の鋼が得られた後、棟金、心金、刃金の3層を鍛接して厚さ20mm、幅40mm、長さ90mm程の材料が4個取れるくらいに打ち伸ばし4個程度に切り離す。