16" x 40" Clausing Automatic Surface Grinders with Delta PLC 7.2” color touch screen controller are constructed of high grade cast iron with heavy walls and reinforced honeycomb ribbing provide excellent rigidity and dampening. Large diameter spindle is supported by four preloaded precision angular contact ball bearings and one NU type roller bearing for durable heavy duty operation, and driven by 7.5 Hp motor that allows highly accurate grinding performance.Enlarged column and base create high stability and rigidity. The maximum height is 24.8” from table surface to the center line of spindle. Hydraulic longitudinal table movement and servo motor drive for cross feed movement, and rapid up/down motor for fast wheel positioning. The saddle rests on precision hand-scraped double V-ways, and the table rests on precision hand-scraped V and Flat ways coated with TURCIT B along with auto lubrication gives excellent wear resistance.Three phase refers to three individual lines that connect to and run voltage through the motor. Each line alternates in a sequence as it reaches its voltage peak. This provides for a more stable flow of voltage and more horsepower to the machine. 230 or 460 voltage, other voltages will need a transformer.