Mitsui Seiki strengthens market-in approach with factory open house

December 18, 2025

Mitsui Seiki Kogyo (Kawajima, Saitama; President: Yoichiro Nasu) held a factory open house at its headquarters plant on November 12 and 13. The event was reservation-based and attracted around 120 visitors over two days. The company exhibited several machine tools, including new models, and also opened its assembly shop to visitors. In addition, an overhauled thread grinding machine originally manufactured in 1981 was displayed, drawing strong interest from attendees.

Improved stability in 5-axis vertical machining center Verte 55X IV

The 5-axis vertical machining center “Verte 55X IV” has improved machining stability compared with previous models. By redesigning the internal structure of the table, the machine reduces the impact of thermal displacement. It maintains machining accuracy even at high spindle speeds and achieves high surface quality during long machining operations, such as mold machining.

Compact internal thread grinding machine developed based on customer needs

The compact internal thread grinding machine “GSS60i” combines a small installation footprint with high machining accuracy. President Nasu stated: “Thread grinding machines had traditionally been large in size, but we developed this new compact model in response to customer requests. We aim to further strengthen our market-in development approach.”