Assist Gas

Assist gas is the compressed gas (typically oxygen, nitrogen, or air) that is blown across the cutting zone during laser cutting to clear away molten material and prevent the molten pool from cooling and solidifying before it exits the kerf. The choice of assist gas is critical to both cutting speed and edge quality, and different materials require different gas types.

For mild and carbon steels, oxygen assist gas is preferred because it reacts exothermically with the molten steel, boosting cutting speed and enabling thick material capability. For stainless steel, aluminum, and other non-ferrous materials, nitrogen assist gas is essential to prevent oxidation and preserve material properties.

The pressure and flow rate of assist gas are programmed parameters that must be optimized for each material and thickness combination to achieve maximum speed without sacrificing edge quality.