Around the 8th century BC, bronze began to be produced locally on the Korean Peninsula. By around the 4th century BC, bronze manufacturing had developed to the point where craftspeople could produce a variety of forms and delicate patterns. Slender bronze swords also emerged around this period. Producing thin yet durable bronze swords represented an important technological advance. Around the 2nd century BC, local iron production began to develop, roughly 600 years after local bronze production had begun. The southeastern region became a major center of iron production thanks to its access to maritime and river transportation and abundant iron resources. The Gaya confederacies later flourished partly through iron production and trade.

Iron production required technology capable of reaching temperatures of around 1,200 degrees Celsius. Experience with such high-temperature technology may have contributed to advances in pottery production. By around the 3rd and 4th centuries AD, high-fired, hard pottery became increasingly widespread. Technological knowledge developed through metalworking may have contributed to this progress. With greater control over fire and materials, manufactured products became increasingly sophisticated.