Star Micronics ST-38

The Star Micronics ST-38 is a turret-type sliding headstock CNC automatic lathe designed for precision machining of large-diameter components up to 38mm (1.5 inches). Sharing the turret-based architecture of its smaller ST-20 sibling, the ST-38 extends the triple-turret approach to the 38mm bar class, delivering massive tooling capacity for complex large-diameter parts that demand Swiss-type precision and single-setup completion.

The main spindle produces 7.5 kW continuous power (11 kW peak) at up to 7,000 RPM, providing the cutting force needed for aggressive machining at 38mm diameters in steel, stainless, and titanium. The sub spindle delivers 5.5 kW continuous (7.5 kW peak) at 7,000 RPM—notably more powerful than the SR-38's 3.7 kW sub spindle, making the ST-38 better suited for demanding back-working operations. The 350mm headstock stroke (315mm with R.M.G.B.) extends well beyond the SR-38's 320mm, accommodating even longer components.

The tooling architecture centers on a front turret with 10 stations (front and back sides), each accepting up to 2 turning tools (16mm shank) or 3 sleeve-type tools. This turret-based approach provides more flexible tool management than gang-type layouts, with rapid indexing to any station. Combined with back-working capability and C-axis control on both spindles, the ST-38 handles complex parts with extensive turning, drilling, milling, and threading operations.

Running on the FANUC 31i-B5 control with a 10.4-inch color LCD display, the ST-38 provides advanced multi-path programming for coordinating turret operations with dual spindle machining. At 6,250 kg and dimensions of 3,477 x 1,859 x 1,865 mm, this is Star's largest turret-type Swiss lathe, requiring substantial floor space but delivering unmatched tooling capacity at 38mm. The revolving guide bush unit is standard for long-part support, with rapid traverse at 30 m/min across all primary axes.