Single-point and Multi-point Machining

Single-point Machining

The tool has a well-defined geometry with only one cutting edge and the part shape is developed by control of the tool path. In turning on a lathe, the tool path may be helical or spiral; hence the machined surface always has axial symmetry. In manual or computer numerical control (CNC) machines, complex shapes can be produced singly or in batches. The size range is enormous, from tiny shafts to generator rotors weighing hundreds of tons. Mass production with hard programmed (cam-driven) screw machines may still be economical, although CNC is being applied. On a planar or shaper the straight tool path creates fundamentally two-dimensional shapes.

Multi-point Machining

The tool used in these processes tool has two or more cutting edges of well-defined geometry. The tool path is simple in drilling, broaching, thread cutting, tapping and often also in sawing and filing. It can however be complex, e.g. in milling and CNC milling with five axes of control are capable of producing the widest variety of shapes, including undercut shapes (Table 4) in a wide range of sizes. Multihead milling machines remove more than 90% of the material for wing surface of jet aircraft.