Cooling too quickly through the brittle temperature range causes the metal to shrink and pull apart. Impurities:

Essentially, your toolpath is "cracking" the integrity of the part because the physics of the cut weren't accounted for in the CAM software.

Dropping the feed rate to 60–80% for the last 5mm of the cut allows the arc to stabilize and the "trail" of the plasma flame to catch up to the torch head, ensuring a cleaner severance. 2. The "Overcut" Technique Under your Jet Operation settings: Overcut: Set this to 2mm–5mm.

A hot crack—often called a "divot," "crater," or "end-of-cut gouge"—occurs at the very end of a cutting sequence. When the plasma torch completes a perimeter, it returns to the exact coordinates where the cut began.