Iron Pillar at Qutub Complex, Delhi
One of the metallurgical masterpieces is the Iron Pillar at Qutub in Delhi made of material which is pure, rustless, malleable iron, a standing monument which has defied for more than a millennium the ravages of time, the wear and tear of weather and the attack of oxidation. Its composition was examined by a Committee of Experts who have held that it was beyond the capacity of any Iron Foundry of that age (c. 400 A.D.) to produce such a finished metallurgical masterpiece.
Another metallurgical masterpiece of ancient India is the Sultanganj colossal image of the Buddha in copper. "It is made of very pure copper, cast in two daggers over an inner core by a sort of circ perdu process. It is 7 feet high and weighs about a ton. A people which was capable of producing such works in stone and iron must have attained considerable proficiency in metallurgy and engineering" [p. 338 of Legacy of India, (Oxford)].