Takes the volume from the thickness, width and length of a plate and multiplies by the density: 7850 kg/m³ for steel, 7930 for stainless and 2700 for aluminium. At the same size, aluminium comes to about a third of steel.
The weight of a plate is simply its volume multiplied by its density.
is the thickness, the width, the length and the density. Steel is 7850 kg/m³, stainless 7930 and aluminium 2700.
A steel plate 9 mm thick, 1500 mm wide and 3000 mm long has a volume of m³ and weighs kg. Four of them come to 1272 kg, or 1.27 tonnes.
A steel plate one metre square and one millimetre thick weighs exactly 7.85 kg. A 9 mm plate a metre square is therefore 70.65 kg, which is a single multiplication. It is a useful anchor for estimating on site.
At the same size, aluminium weighs about a third of steel. The plate above in aluminium comes to 109 kg. For planning a lift or a carry, mistaking the material changes the answer entirely.
Holes and cut corners are not deducted. Subtract them where the area removed is significant.
Sections such as H-beams and angles have complicated shapes and cannot be worked out this way. Take the mass per metre from the section tables and multiply by the length.