Abstract: A flame arresting ventilated wall or panel for an explosion-proof enclosure comprises a stack of aluminum sheets apertured to provide a plurality of discrete, generally parallel gas flow channels disposed in crisscross patterns across the heights and widths of the sheets. Fasteners tie the sheets together into a rigid structure and are disposed in patterns surrounding and individually uniformly supporting the gas flow channels from the center of the sheets to their outer edge. Combinations of three different punched sheets are used, namely, first and second apertured sheets spaced apart by relatively thin separator sheets. Along each of the plurality of gas flow channels, each separtor sheet has a large window and the first and second apertured sheets have separate arrays of nine and sixteen flow holes, respectively, registered with the windows, each array having a total cross-sectional area about one-fourth of each corresponding window.