Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and

Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and
crafts
‘Wootz’ is known to be an anglicised version of ‘ukku’, the word for steel in south India. The term ‘ukku’ may
derive from ‘uruku’, used to describe fused or melted metal in Tamil Sangam literature dated broadly from about
the 5th century BC to 5th century AD, while accounts of the Greek Zosimos of the early Christian era suggests that
the Indians used crucible processes to make metal for swords, i.e. steel. Pliny’s ‘Natural History’ talks of iron from
the Seres which may refer to the ancient south Indian kingdom of the Cheras who are referred to in Sangam
texts. While Thelma Lowe, most of all, and others have made crucial studies on the mechanisms of late medieval
Deccani wootz production, there still remains much to be investigated and clearly established concerning the
antiquity of wootz steel in India and on the identification of ancient artefacts of wootz. It is significant that there
are a couple of analyses reported in early excavation reports from some megalithic sites in southern India of iron
artefacts with 1-2% carbon (for eg. two javelins from megalithic Andhra Pradesh mentioned in Sundara 1999);
however further investigations with micro-structural evidence may be required to ascertain if these can be taken
as conclusive evidence for wootz steel. Investigations by the author on a crucible fragment from the megalithic
site of Kodumanal (3rd century BC) excavated by K. Rajan, Tamil University, found in an iron smelting hearth
showed it to be iron-rich without any other significant metal, which did not rule out the fact that it could belong to
some kind of ferrous process although as yet no clear evidence of metallic remnants could be found in the crucible
(Srinivasan and Griffiths 1997).
Significantly, the author has identified from surface surveys three previously unknown sites for crucible steel
production in southern India (ibid.). Crucibles from one of these sites, Mel-siruvalur in Tamil Nadu shows clear
evidence for the production of a hyper-eutectoid (1.3% C) steel, i.e. a high-carbon steel, probably even by molten
carburisation processes at high-temperatures (Srinivasan 1994, Srinivasan and Griffiths 1997). More significantly,
the site shows signs of megalithic occupation in the vicinity as independently verified by Sasisekaran (2002) while
the author found numerous remains of what appeared to be legs of megalithic sarcophagi in a dried up canal near
the dump. (The megalithic period in southern India ranges in different places from the early 1st millennium BC to
early centuries AD). This site is being further investigated by the author. Other aspects of megalithic iron
production to be touched upon include the iron smelting furnace excavated at Naikund, from the Vidharbha
megaliths of Maharashtra.
As background, this chapter would also briefly explore whether there are technological parameters within the
context of peninsular megaliths which could have supported more advanced metallurgical skills. Previously the
Indian subcontinent had not been associated with a more sophisticated bronze working tradition. However,
metallurgical investigations by the author established for the first time the use of specialized alloys known as hightin
beta bronzes (which are quenched binary copper-tin alloys bronzes of around 23% tin) to make vessels going
back at least to the iron age burials megaliths of the early first millennium BC of the Indian subcontinent which
rank amongst the early such alloys known in the world, and which are still made in parts of India such as Kerala
by similar processes as reported in Srinivasan (1994b, 1997, 1998a) and in papers written by the author with Ian
Glover while at Institute of Archaeology, London (Srinivasan and Glover 1995, 1997). High-tin beta bronzes
generally do not seem to have been in vogue in Europe, and indeed the Greek Nearchus (4th century BC) mentions
that Indians used golden vessels which shattered when dropped which may be interpreted as high-tin bronze, as
suggested by Rajpitak and Seeley (1979). What is significant is that the processes of quenching high-tin bronze
indicates a general familiarity with heat treatment processes in the megalithic period that could have extended to
the knowledge of iron and steel metallurgy. Other evidence for skilled metallurgical activity comes from evidence
suggesting that the deepest old gold mine in the world comes from Hutti in Karnataka with carbon dates from
timber collected from a depth of about 600 feet from a mine going back to the mid 1st millennium BC
(Radhakrishna and Curtis 1991).