This machine is rather like to vertical milling machine in structure. The comparison lies in vertical spindle and table movements, except the jig boring machine is extra inflexible than milling machine. Inflexibility is main to reach the necessary correctness. Jig boring machines are additional classify into two types column type and cross rail type. Column type jig boring machine has bed which carry longitudinal and transverse slide. Column, give at back, supports spindle housing which can vertically attuned. The column type construction is use for lesser machines.
Cross rail type is selected for larger jig boring machine. Bed of this machine has just longitudinal slide, which travel among two vertical columns. Cross slide slides up and down on these columns. The transverse slide is mount on cross rail and houses vertical spindle unit.