The Vale do Aço Metropolitan Region (pronounced [ˈvali du ˈasu], Região Metropolitana do Vale do Aço in Portuguese) is a metropolitan area in Minas Gerais, Brazil, comprising only the four municipalities of Coronel Fabriciano, Ipatinga, Santana do Paraíso and Timóteo, but have an influence area of 22 other municipalities.

Soon after the conclusion of the railway, the ironcasting Belgo-Mineira started its activity in Coronel Fabriciano, buying local timber for charcoal production, using it as fuel for its factories.

In 1948 the municipality of Coronel Fabriciano is emancipated, including in its domains the area of nowadays Timóteo and Ipatinga.

In 1973 Cenibra is installed in Belo Oriente, a municipality located in Vale do aço's influence area.

Lately, imported mineral charcoal was adopted in Usiminas and Acesita, so the eucalyptus is now mainly used to supply the pulp factory of Cenibra as raw material.