Iron pillar of Delhi
Pilar de hierro de Delhi
- Date
- c. 400 · confidence medium
- Place
- Qutb complex, Mehrauli, Delhi, India
- Credited to
- Gupta Empire (Chandragupta II)
- Field
- Matter & energy
What it is
Wrought-iron column over 6 m tall and about 6 t in weight that has barely rusted in sixteen centuries thanks to a protective layer favoured by its high phosphorus content. It is an example of forge-welding large pieces.
Its original location may have been Udayagiri (Madhya Pradesh); it was moved to Delhi, perhaps in the 11th century. The explanation of the passive layer is by Balasubramaniam (IIT Kanpur).
What it led to
- metallurgical studies on corrosion-resistant iron
- symbol of ancient Indian metallurgy