A refers to a crack that appears in a workpiece immediately after cutting, usually near the lead-in, a sharp corner, or the point where the torch finishes the cut. These are not mechanical shear cracks; they are thermal stress fractures .

What and type (steel, aluminum, etc.) are you cutting? What plasma cutter model and amperage are you using?

If the cooling metal is subjected to high tensile stresses while passing through its "brittle temperature range," the grains separate, forming a microscopic or visible crack.

A hot crack is one of the most frustrating defects in CNC plasma cutting. It leaves a deep, unsightly melted crater at the exact point where the torch finishes cutting a shape. This defect ruins the aesthetic appeal of your parts and can compromise their structural integrity.

Understanding and Preventing SheetCam Hot Cracks in Plasma and Laser Cutting

Limitations and cautions

To help troubleshoot your specific issue, could you tell me what and thickness you are cutting? If you know your current lead-in style or feed rate , share those as well so we can optimize your SheetCam profile. Share public link