Coolant Type

Theoretical Background

Cooling vs. Lubrication

Metal cutting is a process of intense plastic deformation. Most of the mechanical work is converted into thermal energy, generating localized temperatures at the shear zone that can easily exceed 800°C to 1000°C when machining steels and superalloys.

Cutting fluids serve two distinct primary functions, depending on the cutting speed ($V_c$) and the material:

Coolant Types in Fusion 360

Fusion 360 provides a comprehensive set of coolant modes. The exact output in the G-code is determined by how these options are mapped to specific M-codes within your CNC machine's Post Processor (.cps file).

Post Processor Mapping (Technical Reference)

For CNC developers and operators, understanding how Fusion 360 passes coolant states to the post-processor is critical. Within the Javascript-based post-processor configuration (.cps), the selected coolant type is accessed via the tool.coolant property.

The internal JavaScript enumeration maps as follows:

// Fusion 360 Coolant Enumeration Constants
COOLANT_OFF = 0;
COOLANT_FLOOD = 1;
COOLANT_MIST = 2;
COOLANT_THROUGH_TOOL = 3;
COOLANT_AIR = 4;
COOLANT_AIR_THROUGH_TOOL = 5;
COOLANT_SUCTION = 6;
COOLANT_FLOOD_MIST = 7;
COOLANT_FLOOD_THROUGH_TOOL = 8;

A typical post-processor implementation translates this property into M-codes like this: