He difference between up milling and down milling is that in down milling the direction of motion of the cutter teeth is opposite the feed direction when the teeth cut into the work
Answers
S.no Up milling Down milling
1 Up milling is also termed as conventional milling. It is also called as climb up milling.
Down milling is also called as climb down milling.
2 The rotary cutter moves against the motion of feed.
The rotary cutter moves in the same direction as that of the feed.
3 Here, while cutting the workpiece from right to left, cutter rotates in anti-clockwise direction.
In down milling, while cutting the workpiece from right to left cutter rotates in clockwise direction.
4 The material from the surface or cutting chips are thrown in the upward direction that’s why it is called as up milling.
Here the situation is opposite to that of up milling as cutting chips are removed in downward direction and therefore, we called it as down milling.
5 It requires a large amount of force compared to down milling.
For down milling, there is a requirement of less amount of force.
6 In up milling, you will get poorer finish.
Here, you will get the best surface finish.
7 The chip width increases from zero and then increases as the process goes on.
Chip width changes from maximum to minimum value.
8 Up milling is mostly used for rough cutting operations.
Down milling is used for finishing operations.
9 Tool wear rate is more as the direction of rotary cutter is against the feed.
Tool wear rate is less as the direction of cutter is in the same direction as that of the feed.
10 Due to increasing tool wear rate, there is reduction in tool life.
Due to reducing tool wear rate, there is enhancement in tool life.
11 It is also famous as traditional way of cutting the surface.
Nowadays, down milling is a better choice than up milling.
12 The cutting forces acts upward.
The cutting forces acts downward.
13 It is mostly used in the cutting of brass, bronze and ferrous materials.
It is mostly applicable to aluminium and aluminium alloys.