MITSUI SEIKI USA will demonstrate the PJ 303X five-axis ultra-high precision vertical machining center at IMTS 2026, at booth #338700 South hall. The PJ 303X is equipped with automation for maximum precision and versatility in processing of workpieces up to 230 mm tall and 280 mm in diameter (9 x 11 inches), and weighing up to 20 kg (44 lbs.) Typical applications cover an extensive range of critical parts, such as lens molds, medical products, EDM electrodes, and fuel cell components.

While Mitsui Seiki machines are well known for heavy-duty machining of large, critical components, the PJ303X is designed to accurately machine smaller parts, offering a positioning accuracy and repeatability of ±0.001 mm.

High-speed linear motor drives move the X-, Y-, and Z-axis 300 mm, 325 mm, and 200 mm (11.8, 12.8, 7.9 inches) respectively. The rapid traverse speed is 20 m/minute (66 ft/min.)

In applications where tight tolerances and complex geometries demand extremely high precision-machining capabilities, the ability to feed material slowly (near to 0.1 mm/min.) on the linear axes allows operators to machine delicate features and perform finishing processes precisely.

Additionally, the PJ 303X provides fine control of rotary-axis speeds at the low end for smooth five-axis interpolation on critical features, improving surface finish and dimensional accuracy. An absolute glass scale feedback system offers full and accurate closed-loop control by determining the exact axis location for each job with no need for additional programming after each power-up, for consistently accurate and repeatable results.

A 50,000-rpm, HSK-E25 taper spindle offers high-speed machining capability. Advanced spindle thermal displacement technology is standard, including a symmetrical gantry column structure that accommodates thermal deformation fluctuations and a thermal compensation mechanism for the machine spindle/head.

Operator-friendly features enhance precision, including a 15-in. color display with touch-panel capability that can be moved to the most convenient position relative to the work envelope.

The PJ303X has the new Fanuc F31i-B5 control, with the i-H Pro control panel. The machine’s double-stage rotary door provides wide access for visibility and set-up.

An automatic tool changer engineered to store up to 24 tools as large as 40 mm (1.57 in.) in diameter and 100 mm (3.9 in.) long provides tooling versatility.

"The PJ303X was engineered to bridge ultra-precision machining with modern automation strategies. For medical, optical, and advanced technology manufacturers, it provides a scalable platform that delivers uncompromising accuracy, process stability, and production efficiency while meeting the industry's most demanding quality requirements," stated Mitsui Seiki’s executive vice president Yasuhide Akimoto.

Learn more at www.mitsuiseiki.com.