The forge near the Basque town of Zestoa was founded in 1978 under the name Talleres Gainza. At the very beginning the production range consisted of machined flanges for the petrochemical industry.

Forging production began in 1980 with the installation of the first hammer. New hydraulic presses together with a ring rolling mill were delivered during the 1990s.

In 2010 the forge was expanded with a massive 5000 t press, enabling to compete with forgings for nuclear and offshore industry.

Since 2018 the company operates under the name Gainza Forge.