 It resembles a specialized species of milling machine that provides tool and die makers with a higher degree of positioning precision (repeatability) and accuracy than those general machines had provided.Although capable of light milling, a jig borer is more suited to highly accurate drilling, boring, and reaming, where the quill or headstock does not see the significant side loading that it would with mill work.The result is a machine designed more for location accuracy than heavy material removal.