Pick a section and size: weight per metre, per part and per batch, plus the area to paint. Hollow sections use the real EN 10219 corner radii, so the figure matches the table instead of running 5 % high.
Accuracy. Nominal weight from nominal dimensions and density. Real stock varies within thickness tolerances (EN 10219-2: ±10 % for t ≤ 5 mm), so allow 2 to 3 % in estimates. Hollow section corner radii to EN 10219-2, angle radii to EN 10056-1; paintable area along the outer contour.
The section is integrated from the real outline: outer corner radius 2t, 2.5t or 3t (EN 10219-2), angle root and toe radii to EN 10056-1.
m = A · ρ. Steel 7850 kg/m³, stainless 7930, aluminium 2700, copper 8960.
25×25×2: 1.36 kg/m; 60×40×3: 4.25; L50×5: 3.77; CHS 48.3×3.2: 3.56. Deviation under 0.3 %.