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Metal weight

Cast iron flat bar weight

Density 0.26 lb/in3 (7.2 g/cm3), typical of gray, class 30.

SheetWeight table
BasisPublished density
Checked2026-09-24
Quick answer

0.5" x 2" cast iron flat bar weighs 3.120 lb per ft (4.64 kg per m). Weight = cross-section area x length x 0.26 lb per cubic inch.

How much does cast iron flat bar weigh per foot?

SizeArea (sq in)lb per ftkg per m12 ft length, lb
0.125" x 1"0.12500.3900.584.7
0.25" x 1"0.25000.7801.169.4
0.25" x 1.5"0.37501.1701.7414.0
0.25" x 2"0.50001.5602.3218.7
0.375" x 2"0.75002.3403.4828.1
0.5" x 2"1.00003.1204.6437.4
0.25" x 3"0.75002.3403.4828.1
0.5" x 3"1.50004.6806.9656.2
0.5" x 4"2.00006.2409.2974.9
0.5" x 6"3.00009.36013.93112.3

Formula: area = width x thickness; weight = area x length x 0.26 lb/in3. For any other size use the metal weight calculator.

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Frequently asked questions

How do you calculate the weight of cast iron flat bar?

Multiply the cross-section area in square inches by the length in inches and by the density, 0.26 lb per cubic inch for cast iron (gray, class 30). For this shape the area is: area = width x thickness. A foot of stock is 12 inches, so weight per foot is area x 12 x 0.26.

How does cast iron compare with steel by weight?

Cast iron is 8% lighter than carbon steel for the same size: 0.26 lb per cubic inch against 0.2836. The same bar or plate in cast iron weighs 0.92 times the steel figure.

Other cast iron shapes

Flat bar in other metals

Keep going

Weights from typical published densities; actual alloys and mill tolerances vary by a few percent. Not an engineering load calculation.