The changing of position of work on a machine consumes time which may add considerably to the expense of large work. The radial drill is so designed that when a piece of work is secured to the drill table, which is placed on a solid foundation for holding very heavy work, the drill spindle may be placed over any part of the work without moving the latter.

There are three classes of radial drills, viz., (1) the plain radial drill, in which the drill spindle is always vertical, but may not be swung over any point of the work; (2) the half-universal drill in which the spindle may be swung over any point of the work and in addition may swing in one plane at any angle to the vertical up to complete reversal of the direction of the drill, and (3) the full-universal drill in which the spindle may be swung in any plane at any angle to the vertical. Fig. 189 shows a universal radial drill the drill spindle of which may be moved to any position within the reach of the machine and placed at any angle desired.

Fig. 190.

Fig. 190.