Steel produced by a method known in ancient India.
The process involved preparation of porous iron , hammering it while hot to release slag , breaking it up and sealing it with wood chips in a clay container, and heating it until the pieces of iron absorbed carbon from the wood and melted. The steel thus produced had a uniform composition of 11.6% carbon and could be heated and forged into bars for later use in fashioning articles, such as the famous medieval Damascus swords. See also bloomery process .