The quality of the iron used in the pillar is exceptionally pure and the detail at the top of the pillar demonstrates the skill of the craftsmen.

Detail showing the inscription of King Candragupta II.

In the Qutb complex of Delhi stands one of the most curious metal objects in the world - the so called “Iron Pillar of Delhi”, which does not seem to rust, despite being over a thousand years old. The height of the pillar, from the top of its capital to the bottom of its base is 7.2 metres, of which 1.1 metre is underground. The base rests on a grid of iron bars soldered with lead into the upper layer of the dressed stone pavement. The pillar's lower diameter is 420 mm (17 in), and its upper diameter 306 mm (12.0 in). It is estimated to weigh more than six tons.”