Due to the poor machinability of stainless steel, there is a higher requirement for the cooling, lubrication, penetration and cleaning performance of the turning fluid.
Commonly used turning fluids have the following categories:

1. Sulfurized oil: A turning oil that uses sulfur as an extreme pressure additive. During the turning process, high-melting sulfide can be formed on the metal surface, and it is not easy to be destroyed at high temperature. It has good lubricating effect and has certain cooling effect, and is suitable for general turning, drilling, reaming and tapping. Vulcanized soybean oil is suitable for drilling, expanding, reaming and other processes. The formula of direct sulfurized oil is: mineral oil 98%, sulfur 2%. The formulation of indirect vulcanized oil is: mineral oil 78% to 80%, vegetable oil or lard 18% to 20%, sulfur 1.7%.

2. Mineral oil such as engine oil and spindle oil:
It has good lubrication performance, but has poor cooling and permeability, and is suitable for external round turning.

3. Vegetable oil: Such as vegetable oil, soybean oil, etc., its lubricating performance is better, suitable for turning threads and reaming, tapping and other processes.

4. Emulsion: Has good cooling and cleaning performance. It also has a certain degree of lubrication and can be used for stainless steel roughing. In turning process, the turning fluid nozzle should be aligned to the turning area, or the high pressure cooling, spray cooling and other cooling methods should be adopted.