Details are provided of a research program which revealed that ancient Chinese foundrymen were producing cast iron artifacts with a spheroidal-graphite structure 2000 years ago. The quality of these archaic irons is similar to that of modern industrial grades of spheroidalgraphite irons. In the absence of spheroidizing agents, heat-treatment is pointed to as the likely manufacturing route in achieving a uniform distribution of compact well-shaped spheroids. This was confirmed by subjecting a specimen of as-cast white Han Wei iron to a heat-treatment cycle. The subsequent examination revealed graphite spheroids. See also AATA 20-998. -- AATA