The Mazak Multiplex 4200 is a twin-spindle twin-turret CNC lathe with a reputation for lights-out reliability that made it a mainstay in high-volume turned-parts shops, from bushing and fitting houses to automotive component manufacturers. This 2004 build features twin opposing A2-6 main spindles with 2.4-inch bores, 35-5,000 RPM speed ranges, 30 HP motors each, and 258.2 ft-lbs of torque, paired with twin 12-position dodecagonal drum turrets taking Modified VDI tool holders and indexing in 0.2 seconds per step. Axis travels cover 9.06 inches on X with Z travels of 17.25 inches on the left and 19.37 inches on the right, rapids reach 1,200 IPM on X and 1,300 IPM on Z, and the working envelope handles a 12.5-inch swing, 2.0-inch bar capacity, and shaft work up to 21 inches between spindle faces. Running on the Mazatrol Fusion 640T control, the machine ships with the GL100F gantry loader, EIA/ISO option package, PCMCIA interface, LAN and modem network interface, high-power coolant at 105 PSI and 5.3 GPM on each spindle, automatic tool eye on both turrets, LP2 probing prep, and a Jorgensen magnetic slider bed conveyor — a complete lights-out chucker setup weighing 16,060 pounds on a compact 81.54 by 140.6 inch footprint.
Compared to Mazak's earlier twin-spindle Multiplex-series lathes — the Multiplex 6200, 6200Y, and the original Multiplex 6250 that relied on the older Mazatrol T-Plus and T32 controls — the Multiplex 4200 with the Fusion 640T represents a real generational step up rather than just a newer build date. The Fusion 640T replaces the older T-Plus and T32 interfaces with a faster processor, PCMCIA and LAN connectivity for modern program transfer, and a more intuitive Mazatrol conversational environment that shortens setup cycles on complex two-spindle parts. The 4200's compact 12.5-inch swing and 2.0-inch bar capacity purpose-build the platform for high-cycle small-part production, with a tighter footprint, faster 0.2-second turret indexing, and factory-integrated GL100F gantry loading that earlier Multiplex configurations required as a bolt-on secondary automation project. Add the LP2 probing prep, automatic tool eye on both turrets, and high-power coolant already installed, and the buyer is stepping into a purpose-built lights-out chucker at a used price — not a generic twin-spindle lathe that still needs to be equipped for unattended production.