Fixing dross when laser cutting stainless steel

Dross on the lower surface means molten metal is not being fully expelled. Adjustment order: 1) Focus: lower the focus first, typically to -1 or -2 mm, and check whether dross decreases. 2) Speed: reduce speed slightly, but too slow increases heat input and worsens dross. 3) Gas pressure: insufficient nitrogen pressure is a common cause. For 6 mm plate, 14-16 bar is typical; excessive pressure creates turbulence. 4) Nozzle: check concentricity and bore diameter. A worn nozzle deflects the gas jet. 5) Material: confirm the surface is free of oil and rust, which affect absorption. Change one parameter at a time and record cut quality.