A year before Komatsu Indonesia's Fabrication Plant was established, the company had been supporting global outsourcing activity of casting demand.

The Foundry Plant was established in 1991 to support global outsourcing activity. In the beginning, the plant was equipped with a capacity of around 300 tons/month of casting production, then increased up to 900 tons/month. In 2005, the company expanded its Foundry Plant which made a total capacity up to 1.600 tons/month. Up to this day, the maximum capacity of the Foundry Plant reach up to 2.000 tons/month.

The main facilities of these plants consist of basic arc furnace, induction furnace, molding line with sand mixer, sand reclamation facility, finishing, and heat treatment facility. The main production of this plant is casting parts for bulldozers, main frame for dump trucks, boom, arm, and undercarriage parts of hydraulic excavator.