Cylindrical turning on an engine lathe
Facing on a vertical boring machine
Internal boring on a horizontal boring machine
Production of a flat surface on a shaper
- Most extensively used machining process, carried out on a wide range of lathes from the simplest engine lathe to the most complex multi-spindle NC lathe.
- Machines can be horizontal or vertical, and are used mainly for heavy, large diameter workpieces that cannot be turned on a lathe.
- Machines are usually horizontal, and process is slow since 2/5 of the time is spent on the return stroke. Largely replaced by milling.
- Single point cutting can be carried out on almost any material whose hardness is less than that of the cutting tool material.
- Economic machining of a material depends on many factors: hardness of material, hardness and toughness of cutting tool, design of cutting tool, cutting fluid, metal removal rate, surface finish, tolerance, feed, speed, etc.
- Mainly for producing cylindrical (turning), flat (facing) or shaped (tapers, threads, etc.) surfaces.
- Tolerances vary from ±0.5 mm (rough turning) to ±0.1 mm (fine turning).
- Roughness varies from 25 µm Ra (rough turning) to 0.05 µm Ra (fine turning), but is typically 0.5–5 µm Ra.
- Mainly for facing, hole cutting and enlarging/truing drilled or turned holes in large components.
- Tolerance and roughness as for turning.
- Mainly for roughing and finishing flat surfaces, although arcs and special forms can be generated.
- Shapers used for smaller components than planers.
- Tolerances are typically ±0.05–0.1 mm.
- Roughness varies from 50 µm Ra (roughing) to 0.5 µm Ra (finishing), but is typically 1–25 µm Ra.
This article is a part of Manupedia, a collection of information about some of the processes used to convert materials into useful objects.