Laser cutting mild steel

Laser cutting mild steel is available in five thicknesses: DC01 (1.5 mm) and S235 (2–5 mm), cut with oxygen. It is the usual choice for structures, brackets and welded parts - but the edge can show oxide scale and discolouration, and from 3 mm also spot marks and slight discolouration where the sheet rested on the teeth of the cutting grate. Burr on the edges is not an issue, even at 5 mm. Without a coating the steel starts to rust. It can be painted or galvanised; before powder coating, it is worth cleaning the scale off an oxygen-cut edge.