English Author: Site Editor Publish Time: 2025-10-27 Origin: Site
Iv. Processing Motion Forms: "Single Feed" vs "Multi-axis Compound"
The different combinations of the main motion and feed motion of the two determine the difference in processing flexibility:
Turning motion: The form of motion is single, with only two core motions:
Main motion: The rotational motion of the workpiece around its own axis (fast speed, usually 100-6000r/min);
Feed motion: The axial feed of the tool along the workpiece's axis (turning the outer circle/inner hole) or the radial feed along the radial direction (turning the end face/cutting off) is both linear motion.
Therefore, turning can only process "surfaces symmetrical around an axis" and is unable to process complex curved surfaces.
Milling motion: The motion form is more flexible and can achieve multi-axis compound motion
Main motion: The rotational motion of the milling cutter around its own axis (at a faster speed, typically 1000-10000r/min, and can reach tens of thousands of r/min in high-speed milling);
Feed motion: The workpiece moves in A straight line along the X/Y/Z axis of the worktable (for example, it moves along the X-axis when machining a plane and along the Y-axis when machining a groove), and can even be combined with the rotation axis (A/B/C axis) to achieve "five-axis milling", processing complex spatial curved surfaces (such as aero engine blades).
V. Machining Accuracy and Surface Roughness
Under conventional processing conditions, there are differences in the precision and surface quality between the two (high-precision processing requires adjustment in combination with the performance of the machine tool) :
| processing method | machining precision | surface roughness | key influence factor |
| turning | It is relatively high, usually reaching IT7-IT8 grades (precision turning can reach IT5-IT6 grades). | Better, usually 1.6-6.3 μm(fine turning can reach 0.8-0.4μm) | Workpiece rotational stability (spindle runout), cutting edge accuracy of turning tools |
| milling | Medium, usually reaching IT8-IT9 grades (precision milling can reach IT6-IT7 grades) | Medium, usually 3.2-12.5μm (fine milling can reach 1.6-0.8μm) | The number of milling cutter edges (more edges for greater stability), uniformity of worktable feed, and tool marks (easier to produce in multi-path processing) |
Vi. Processing Efficiency
The efficiency differences need to be judged in combination with the processing scenarios and cannot be generalized.
Turning: Suitable for large-scale continuous processing of rotary body parts (such as mass production of bolts and shafts). Advantages: Single-edge continuous cutting, no "idle travel" (the tool is always in contact with the workpiece), and a simple processing flow (no need for frequent tool changes), with high batch efficiency.
Milling: Suitable for processing complex parts with multiple varieties and medium to small batch sizes (such as molds and boxes). Advantages: Multi-edge alternating cutting, fast cutting speed (high-speed milling efficiency far exceeds ordinary turning), and can complete multi-face processing (such as milling planes + milling grooves) in one clamping. However, for simple rotating bodies, the efficiency is lower than that of turning (the feed path needs to be adjusted multiple times).
Vii. Summary: How to Choose Turning and Milling?
If processing rotating parts such as shafts, discs, sleeves, and threads, turning is preferred (with high efficiency and good precision).
If processing non-rotary parts such as planes, grooves, boxes, and complex contours, milling (which is highly flexible and can be combined with multiple axes) is preferred.
If a part contains both rotary and non-rotary features (such as a "shaft with a flange"), a combined processing of turning and milling is usually required (turning the shaft body and milling the holes or grooves on the flange).
