Ancient Hindu marvel-Ashoka Iron Piller

Ancient Hindu marvel! Marvelous
For the last 1600 years, the rustless wonder called the Iron Pillar of India, near the Qutub Minar at Mehrauli in Delhi, continues to stay strong!
The pillar, made up of nearly seven tonnes of 98 per cent wrought iron of pure quality, is 7.21 m (23 feet 8 inches) high, with 93 cm buried below the present floor level, and has a diameter of 41 cm (16 inches).
A team at the Archaeological Survey of India also came to the conclusion that the pillar was not cast but fabricated by forging and hammer-wielding lumps of hot pasty iron, weighing 20 to 30 kg, in a step-by-step process. The surface of the pillar retains marks of hammer blows. It is assumed that 120 laborers took a fortnight to complete this daunting task.
Experts at the Indian Institute of Technology, Kanpur, believe that the relatively pure composition of the iron used, presence of high amounts of phosphorus (as much as 1 per cent against less than 0.05 per cent in today’s iron) and absence of sulphur/magnesium in the iron are the main reasons for its longevity.A thin layer of ‘misawite’ (formed catalytically by the presence of phosphorous in the iron), a compound of iron, oxygen and hydrogen, has also protected the pillar.
This is a demonstration of the high degree of accomplishment in the art of steel making by ancient Indian steel makers. It has been claimed that the Indians were the only non-European people who manufactured heavy forged pieces of steel and the pieces were of the size that the European smiths did not learn to make more than 1000 years later.