How this calculator works
Carbon steel starts at 7850 kg/m3 from the Saarstahl bar-steel EPD; the stainless reference is Alleima Sanmac 304/304L at 7900 kg/m3. Square and rectangular hollow sections use sharp corners, so formed corner radii and mill tolerances can cause differences from catalogue masses.
Formula
Vpiece = face area x thickness; Vbatch = quantity x Vpiece; mass = density x Vbatch; thickness = mass / (density x quantity x face area). Circular area = pi x diameter^2 / 4. Hollow sections subtract the inner section. Sphere V = pi x D^3 / 6; torus V = 2 x pi^2 x R x r^2. Can V = annulus area x overall height + inner area x (base + lid thickness).
Worked example
A 2 m by 1 m carbon-steel plate at 10 mm thickness weighs 157 kg. A measured total of 314 kg for one such plate corresponds to 20 mm thickness.
Advertisement
Frequently asked questions
Does every steel grade have the same density?
No. The references cover carbon steel and one stainless family. Use custom density for tool steels, iron or another alloy rather than assuming a grade-specific value.
Is the hollow-section mass a certified catalogue value?
No. This geometric estimate ignores formed corner radii, weld beads and dimensional tolerances. Use the mill table for procurement where those differences matter.
What width is used for hexagonal bars?
Enter the side length. If a stock size is across flats, divide that measurement by the square root of three to obtain a hexagon side.