Steel Density Table — Weight per Unit Volume Reference

Steel density is a fundamental property used in dead load calculations, weight estimates, and material takeoffs. Structural carbon steel has a density of 490 lb/ft^3 (7,850 kg/m^3). This page provides density values by steel grade, weight-per-length tables for common shapes, unit conversions, and worked examples.

Structural steel density

This value applies to all common structural carbon steels: ASTM A36, A572, A992, A500, A53, A913, and their international equivalents (AS/NZS 3678/3679, EN 10025 S235/S275/S355). Alloy composition variations have negligible effect on density -- all structural steels are within 0.5% of 490 pcf.

Density by steel grade

Carbon steel grades

Despite differences in yield strength, all carbon steel grades share the same density of 490 lb/ft^3 (7,850 kg/m^3). Density is determined by the iron crystal structure, not by alloying or heat treatment.

High-strength steel grades

High-strength low-alloy and quenched-and-tempered steels share the same density. Alloying elements (Cr, Ni, Mo, V) are present in small enough quantities that density remains 490 lb/ft^3.

Stainless steel grades

Stainless steels are approximately 2% denser than carbon steel due to higher chromium and nickel content.

Weathering steel grades

Weathering steels develop a protective oxide patina and have the same density as standard carbon steel.

Density of related structural materials

Weight per linear foot for common steel shapes

W-shapes (wide-flange)

The designation tells you the weight directly. A W16x40 is a wide-flange section nominally 16 in deep, weighing 40 lb/ft (59.5 kg/m). For any shape, the quick formula is:

Weight (lb/ft) = Area (in^2) x 3.4

Derived from: 490 lb/ft^3 / 144 in^2/ft^2 = 3.403, rounded to 3.4.

HSS (hollow structural sections)

Round HSS formula: Weight (lb/ft) = pi x (OD - t) x t x 3.4, where OD = outside diameter (in), t = wall thickness (in).

Plate steel weight

Weight (lb/ft^2) = thickness (in) x 40.8

Total plate weight formula: Weight (lb) = L (in) x W (in) x t (in) x 490 / 1728

Steel weight for dead load calculations

In dead load calculations, the self-weight of steel framing is typically estimated as:

These are preliminary estimates for initial sizing. Final dead loads must be calculated from actual member sizes.

Unit conversion reference

Density across design codes

Steel density is a material property, not a code-dependent value. Carbon structural steel is 7850 kg/m^3 (490 lb/ft^3) regardless of the design standard:

• AISC 360 (US): 490 lb/ft^3 (7,850 kg/m^3)
• AS 4100 (Australia): 7,850 kg/m^3
• EN 1993 (Eurocode 3): 7,850 kg/m^3
• CSA S16 (Canada): 7,850 kg/m^3

What differs between codes is how density feeds into load combinations and safety factors -- not the fundamental material property itself.

Common mistakes

1. Using 480 lb/ft^3 for steel. Some older references use 480 pcf. The AISC-accepted value is 490 pcf (7,850 kg/m^3).

2. Confusing density with unit weight. Density is mass per volume (kg/m^3). Unit weight is force per volume (kN/m^3 or pcf). In US practice, "density" in pcf is actually unit weight (since 1 lb-mass weighs 1 lb-force at standard gravity).

3. Not including connection weight. Connections typically add 5-15% to the steel member weight. For material takeoffs, a connection allowance of 10% is common.

4. Using normal-weight concrete density for lightweight concrete. Lightweight concrete is 110 pcf vs. 150 pcf for normal-weight. Using the wrong value significantly affects dead load calculations.

5. Forgetting fireproofing weight. Spray-applied fireproofing adds 1-3 psf depending on the required thickness and rating.

Frequently asked questions

What is the density of structural steel? 490 lb/ft^3 (7,850 kg/m^3). This applies to all common structural carbon steels (A36, A992, A572, etc.) and varies by less than 0.5% across grades.

How do I calculate the weight of a steel plate? Weight (lb) = length (in) x width (in) x thickness (in) x 490 / 1728. Or use the quick formula: weight per square foot = thickness (in) x 40.8 lb/ft^2.

What is the difference between density and unit weight? Density is mass per unit volume (kg/m^3). Unit weight (or specific weight) is weight per unit volume (kN/m^3 or pcf). In US customary units, the numerical values are the same because 1 lbm = 1 lbf at standard gravity.

Does steel density change with grade or strength? No. All carbon structural steels, from A36 (Fy = 36 ksi) to A514 (Fy = 100 ksi), have the same density of 490 lb/ft^3 (7,850 kg/m^3). The strength difference comes from alloying and heat treatment, which affect microstructure but not overall density. Stainless steels (304, 316) are slightly denser at approximately 500 lb/ft^3 (8,000 kg/m^3).

How much weight should I add for connections? A common rule of thumb is to add 10% to the raw member weight to account for connection material (gusset plates, clip angles, bolts, weld metal). For heavily braced structures this may be 12-15%; for simple connections, 5-8% may suffice.

Why do some references use 480 pcf instead of 490 pcf? Older editions of some design manuals used 480 pcf as a rounded estimate. The current AISC-accepted value is 490 pcf (7,850 kg/m^3). Using 490 pcf adds approximately 2% to weight estimates compared to 480 pcf.

Density by alloy — carbon, stainless, aluminum, and copper

Different steel alloys and competing metals have distinct densities that affect weight calculations, dead load estimates, and material selection.

Steel and metal alloy density table

Unit weight calculation example

Calculate the weight of a 10 ft long W16x36 beam:

Weight = density x volume
Volume = A x L = 10.6 in^2 x (10 x 12) in = 1,272 in^3
Density = 490 lb/ft^3 = 0.2836 lb/in^3

Weight = 0.2836 x 1,272 = 360.7 lb

Cross-check: W16x36 = 36 lb/ft x 10 ft = 360 lb (matches within rounding).

Weight estimation formulas for common shapes

Steel weight by section type — comparison for 20 ft span

The W-shape provides the highest strength-to-weight ratio for bending applications, while HSS sections provide superior torsional resistance and architectural appearance at a modest weight premium.

Run this calculation

• Plate Weight Calculator -- compute steel plate weight by dimension and thickness
• Steel Weight Calculator -- estimate the weight of standard steel shapes
• Unit Converter -- convert between imperial and metric units

Related references

• Structural Steel Weights -- weight tables for W-shapes, HSS, angles, and channels
• Plate Weight Reference -- detailed plate weight tables by thickness
• Steel Grades -- properties and specifications for common structural steel grades
• AISC Steel Construction Manual Reference -- AISC design tables and specifications
• How to Verify Calculations -- quality control procedures for structural calculations
• Bolted Connection Design -- design and analyze bolted steel connections
• Welded Connection Design -- design and analyze welded steel connections
• Base Plate Design -- design column base plates for steel columns
• Structural Steel Shapes -- dimensions and properties for standard steel sections

Disclaimer

This page is for educational and reference use only. It does not constitute professional engineering advice. All design values must be verified against the applicable standard (AISC 360, AS 4100, EN 1993, CSA S16) and project specification. Density values are nominal and may vary slightly based on specific mill production. The site operator disclaims liability for any loss arising from the use of this information.