| Name |
Conventional milling |
Climb milling |
| Definition |
In up milling, the milling cutter rotates in a direction opposite to the feed direction of the work piece. |
In down milling, the direction of milling cutter rotation is the same as the work piece feed direction. |
| Rotation of cutter |
Rotation of cutter and feed are opposite. |
Rotation of cutter and feed are the same. |
| Force direction |
In up milling, the material is removed by the resultant force. |
In down milling, the resultant force presses the work piece against the cutter. |
| Chip direction |
Chip thrown in upward direction by milling cutter. |
Chip thrown in downward direction by milling cutter. |
| Surface finishing |
In up milling, poor surface finishing is achieved, making it suitable for roughing operations. |
In down milling, a better surface finish is achieved, making it suitable for finishing operations. |
| Backlash |
Some backlash. |
Backlash free. |
| Chip thickness |
In up milling, chip thickness varies from minimum to maximum. |
In down milling, chip thickness varies from maximum to minimum. |
| Heat diffuse |
In up milling, heat diffuses towards the material, potentially changing work piece properties. |
In down milling, heat diffuses towards the chip, keeping work piece properties unchanged. |
| Tool wear |
More tool wear. |
Less tool wear. |
| Fixture |
Due to high load on the work piece, holding devices like fixtures are required in up milling. |
In down milling, fixture requirements are minimal. |
| Coolant |
Difficulty in pouring the coolant just on the cutting edge due to the nature of the cut. |
The coolant can be poured at the cutting zone where cutting force is maximum. |
| Burr |
Burr is formed only on the unfinished surface ahead of the relative tool feed; however, the majority of such burrs are removed in subsequent passes. |
Burr is formed at the finished surface on the opposite side of the relative tool feed, and these burrs are not removed automatically, degrading cutting quality. |
| Cost |
In up milling, overall cost is comparatively high due to high tool wear and fixture requirements. |
In down milling, overall cost is lower. |
| Material |
For brittle materials like ceramics, up milling is useful. |
In the case of brittle materials, down milling is not a viable process. |
