Difference between dry milling and wet milling

Milling process is essentially an intermittent processing process. This will cause the temperature at the cutting edge to fluctuate between high temperature (about 1000 ℃) and low temperature.

01 Effect of cutting fluid

When the cutting edge cuts in and out, the temperature change will intensify. Therefore, the cutting edge will be subject to thermal shock and periodic stress, which may lead to cracks and, in the worst case, may lead to the premature end of the effective life of the tool.

The higher the temperature in the cutting area, the less suitable the cutting fluid is.

In the finishing process, the use of cutting fluid will not shorten the tool life as much as in rough machining due to the reduced heat generated.

02 Dry milling

Dry milling can prolong the life of the cutting edge. The temperature does change, but it will remain within the design range of cemented carbide materials.

Rough milling should always be carried out without using cutting fluid.

03 Wet milling with cutting fluid

There are some exceptions to the use of cutting fluids:

1) Stainless steel and aluminum alloy finishing – used to prevent metal particles from adhering to the surface structure

2) Milling superalloys at low cutting speeds – for lubricating and cooling parts

3) Cast iron milling, used to wet and wash away dust to protect environment and health and ensure part accuracy

4) Milling of thin-walled parts to prevent geometric deformation

5) When machining deep cavities, a micro lubrication system (i.e. compressed air containing a small amount of special oil) can be used to assist in chip removal

Generally, dry milling is selected for rough milling and wet milling is selected for finish milling