Tamahagane
When the liquid slag is drawn out and the process is finished, the clay tub is broken and the KERA (raw iron block) is removed. The best steel with highest carbon content is near the vents of the blower system, because this is the where the reduction process is strongest. The quality of tamahagane is determined by its breaking structure, but it is important to knowe that there are different types of TAMAHAGANE needed to forge a sword blade.