Compared to other contemporary cultures in Central Vietnam and Southeast Asia, the Dong Son culture stood out thanks to its fins bronze-wares. Tens of thousands of Dong Son bronze items have been found. These items were designed to serve people's work and daily needs. Housewares include situla (large bucket-shaped vessels), post, jars, vases, kettles, ladles, spoons, bowls, plates, and lamps, etc. Agricultural tools include axes, ploughs, hoes, and shovels, etc. Dong Son people made sickles to harvest their crops more efficiently than previous tools, which could only cut one ear of rice at a time. Tools for carpentry include various chisels. Weaving developed during this period thanks to new wearing tools. Apart from ceramic shuttles, there were specialised bronze tools such as knives and brushes. Some knives had flat handles with small spikes like those on a brush. This specialised weaving tool combined two functions: to cut and to brush. Dong Son hunting tools and weapon include various weapon of attack and defence, such as spears, daggers, battle axe, javelins, shields, bows and arrows, etc. Other items such as musical instruments, ritual objects, jewellery, and statues are plentiful in terms of quantity, type and design.
Where these items made by Dong Son people or were they imported? there is a great deal of persuasive archaeological evidence to show that Dong Son people were skilful bronze-casters. Moulds made from stone, sand and terracotta; and pots made from clay mixed with chaff and plants used to melt bronze were found in Ca village (Phu Tho province), Vac village (Nghe An province) and some others sites. Opened moulds were used to cast animal statues were found at Lang Ngam (Bac Ninh province). Two-part moulds were used to cast small objects such as bells, daggers, axes and spears. At the Co Loa Citadel in Hanoi, hundreds of pieces of moulds used to cast arrows have been found. Bronze drums were cast with disposable three-part moulds. After casting, the mould was broken to remove the finished drum. Therefore, it is difficult to find remnants of this type of mould. To date, only one part of a bronze drum-casting mould has been found in Luy Lau, Bac Ninh province.
Metal-working reached surpri-singly high standards during the Dong Son civillisation. The most outstanding examples are bronze drums and situla of large sizes with well-proportioned shapes and skilful and distinctive patterns. Hundreds of bronze drums have been found in the area where the Dong Son culture existed. Some Dong Son drum have also been found in other parts of sophisticated ones such as Ngoc Lu, Hoang Ha, Song Da and Co Loa were found in Vietnam. Dong Son drums showcase the skilful, creative and advanced bronze-casting techniques and artistry of DOng Son people.
In the cultures that preceded the Dong Son culture, such as Phung Nguyen, Dong Dau and Go Mun, the metal alloys consisted of two elements: copper and tin. During the Dong Son culture, there were significant advances. People could produce various types of alloys, using copper, lead and tin as the three main elements. Adding a proportion of lead to the alloy allows the melted metal to full up every narrow corner of the mould, resulting in a smooth finished product. Therefore, Dong Son people could produce better products in terms of size, shape and decorations. Moreover, they learned to adjust the ratio of metal elements in the alloy according to the type and usage of each product. For example, sharp pointed objects such as chisels, axes, arrows, and daggers were made from an alloy of copper and tin; large-sized objects with detailed patterns were made from an alloy containing lead.
With these great developments, metal casting in the Dong Son culture became an independent industry that required specialisation and a clear distribution of labour. Part of the population stopped working in agriculture to mine and process ore or cast bronze. Evidence for this specialisation lies in the tomb of a coppersmith found in a burial ground in Ca village. The man was buried with four moulds including a bell mould, an axe mould, a spear mould and a sword-hilt mould. A copper melting pot was also found. Inside the Co Loa bronze drum found in Ma Tre field, Co Loa, Ha Noi in 1982 were many ploughs and bronze pieces that had been cllectec to recycle. The Co Loa bronze drum is one of the most sophisticated drums found. This suggests that its owner was a rich person with great power and influence.
The development of metallurgy spurred the growth of the other economic sectors thanks to the availability of more advanced and efficient tools. Improved metalworking skills allowed the economy and society to develop, making the Dong Son civilisation stand out compared to previous cultures. This created the basics for the formation of Van Lang - Au Lac, the first nation of the ancient Vietnamese people.