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Engineering Materials Properties Reference

Density · E · Yield/UTS · Poisson · Thermal Conductivity · CTE

When to use: Look up standard published mechanical and thermal properties for common structural and machine-design materials — steel, stainless steel, aluminum, cast iron, copper alloys, titanium, plastics, concrete, and wood. Search or filter by category, switch between SI and US customary units, and select up to 3 materials for a side-by-side comparison.

14 of 14 materials shown. Check up to 3 in the "Compare" column to build a side-by-side comparison below.
CompareMaterialCategoryDensityModulus EYieldUTS/StrengthPoisson νThermal kCTE α
Structural Steel A36Steel7,850 kg/m³200.0 GPa250 MPa400.0 MPa (Tensile UTS)0.2651.90 W/(m·K)11.7 µm/m·°C
Structural Steel A992Steel7,850 kg/m³200.0 GPa345 MPa450.0 MPa (Tensile UTS)0.2651.90 W/(m·K)11.7 µm/m·°C
Stainless Steel 304Stainless Steel8,000 kg/m³193.0 GPa215 MPa505.0 MPa (Tensile UTS)0.2916.20 W/(m·K)17.3 µm/m·°C
Stainless Steel 316Stainless Steel8,000 kg/m³193.0 GPa205 MPa515.0 MPa (Tensile UTS)0.2816.30 W/(m·K)16.0 µm/m·°C
Aluminum 6061-T6Aluminum2,700 kg/m³68.9 GPa276 MPa310.0 MPa (Tensile UTS)0.33167.00 W/(m·K)23.6 µm/m·°C
Gray Cast Iron (A48 Class 30)Cast Iron7,200 kg/m³110.0 GPa207.0 MPa (Tensile UTS (brittle))0.2652.00 W/(m·K)10.8 µm/m·°C
Copper C11000 (annealed)Copper Alloy8,940 kg/m³117.0 GPa69 MPa220.0 MPa (Tensile UTS)0.34391.00 W/(m·K)17.0 µm/m·°C
Brass C26000 (annealed)Copper Alloy8,500 kg/m³110.0 GPa105 MPa300.0 MPa (Tensile UTS)0.34120.00 W/(m·K)20.0 µm/m·°C
Titanium Ti-6Al-4VTitanium4,430 kg/m³113.8 GPa880 MPa950.0 MPa (Tensile UTS)0.346.70 W/(m·K)8.6 µm/m·°C
PVC (Rigid, Type I)Plastic1,400 kg/m³3.0 GPa52 MPa52.0 MPa (Tensile Strength)0.400.19 W/(m·K)52.0 µm/m·°C
ABSPlastic1,050 kg/m³2.3 GPa40 MPa44.0 MPa (Tensile Strength)0.350.20 W/(m·K)90.0 µm/m·°C
Concrete (f'c = 4,000 psi)Concrete2,400 kg/m³24.9 GPa28.0 MPa (Compressive f'c)0.181.70 W/(m·K)10.8 µm/m·°C
Wood — Douglas Fir (clear, ∥ grain)Wood530 kg/m³13.4 GPa53.1 MPa (Bending MOR ∥ grain)0.350.12 W/(m·K)3.8 µm/m·°C
Wood — Southern Pine (clear, ∥ grain)Wood580 kg/m³13.7 GPa60.3 MPa (Bending MOR ∥ grain)0.330.14 W/(m·K)3.9 µm/m·°C
Side-by-Side Comparison
Structural Steel A36
Steel
Density7,850 kg/m³
Modulus E200.0 GPa
Yield250 MPa
Tensile UTS400.0 MPa
Poisson ν0.26
Thermal k51.90 W/(m·K)
CTE α11.7 µm/m·°C
Aluminum 6061-T6
Aluminum
Density2,700 kg/m³
Modulus E68.9 GPa
Yield276 MPa
Tensile UTS310.0 MPa
Poisson ν0.33
Thermal k167.00 W/(m·K)
CTE α23.6 µm/m·°C
References
ASM Handbook, Vol. 1 & 2 — Properties and Selection
AISC Steel Construction Manual — A36/A992
USDA Forest Products Laboratory — Wood Handbook (FPL-GTR-282)
ACI 318 — Concrete modulus of elasticity, Ec = 57,000√f’c (psi)

About the Engineering Materials Properties Reference

This reference table collects standard, widely-published mechanical and thermal properties for the material families most commonly encountered in mechanical and structural engineering — carbon and stainless steels, aluminum, cast iron, copper alloys, titanium, common plastics, concrete, and structural wood species. Values shown are representative, commonly cited figures (comparable to ASM Handbook, AISC, ACI 318, and USDA Wood Handbook data) intended for preliminary design, coursework, and quick comparison — always verify against a certified mill test report or the governing design code for final engineering calculations.

What each property means

Density (ρ) is mass per unit volume, used for weight and inertia calculations. Modulus of elasticity (E, Young's modulus) relates stress to elastic strain (σ = Eε) and governs deflection and stiffness. Yield strength is the stress at which a metal begins to deform plastically (permanently); many brittle materials (cast iron, concrete, wood) do not have a well-defined yield point and are instead characterized by ultimate tensile, compressive, or bending strength. Poisson's ratio (ν) is the ratio of lateral to axial strain under uniaxial load, needed for multiaxial stress analysis and for relating E to the shear modulus (G = E/(2(1+ν))). Thermal conductivity (k) governs heat transfer rate through the material by conduction. The coefficient of thermal expansion (CTE, α) gives strain per degree of temperature change, critical for thermal stress analysis and for detailing expansion joints in structures with temperature swings.

Why these values vary in practice

Published "typical" property values represent averages or minimums from a population of test specimens and can vary meaningfully with alloy composition, heat treatment/temper, cold work, grain direction (especially in wood), moisture content (wood and some plastics), and temperature. Structural steel and aluminum properties are relatively tightly controlled by ASTM/AISI/AA specifications, so published values are reliable for design when the correct grade and temper are specified. Cast iron, concrete, and wood are far more variable — concrete strength depends on mix design, curing, and age; wood properties depend heavily on species, grade, moisture content, and load direction relative to grain; cast iron properties depend strongly on graphite flake morphology and section thickness (cooling rate). Always use code-mandated design values (AISC, ACI 318, NDS) rather than reference-table clear-material values for final structural design.

How to use the comparison tool

Use the search box or category filter to narrow the table, then check the "Compare" box (up to 3 materials) to generate a side-by-side comparison card below the table showing every property for the selected materials at once — useful for material substitution studies (e.g., comparing 6061-T6 aluminum against A36 steel for a weight-critical bracket, or 304 vs. 316 stainless for a corrosive environment where 316's added molybdenum improves chloride resistance at a modest strength trade-off). Toggle between Metric (SI) and US Customary units at any time; the underlying data is stored once in SI and converted on the fly so the two unit systems always stay consistent.

Frequently asked questions

Why do steel and aluminum have such different strength-to-weight implications despite steel having roughly 3× aluminum's modulus?

Aluminum 6061-T6 has about one-third the density of steel and about one-third its modulus of elasticity, so for a given cross-section, an aluminum member deflects roughly the same as steel per unit weight — but aluminum has a much lower absolute stiffness, meaning aluminum structures often need larger cross-sections to control deflection, even though they can be competitive or superior on a strength-to-weight basis for strength-governed (rather than deflection-governed) designs.

Why does 316 stainless steel cost more than 304, and when is it worth it?

316 stainless adds 2–3% molybdenum to the 304 composition, which substantially improves resistance to pitting and crevice corrosion in chloride-containing environments (seawater, de-icing salts, many chemical process streams). For general food service, architectural, and dry indoor use, 304 is usually adequate and less expensive; 316 is worth the added cost in marine environments, chemical processing, and pharmaceutical equipment.

Why doesn't cast iron or concrete have a yield strength listed?

Both are brittle materials: they do not exhibit a distinct transition from elastic to plastic deformation the way ductile metals do. Instead, they behave approximately linearly elastic up to fracture (cast iron in tension) or up to crushing (concrete in compression). Engineers instead design using ultimate tensile/compressive strength with substantial safety factors, and — for concrete — using strength-reduction (φ) factors per ACI 318 rather than a yield-based approach.

Why is wood's coefficient of thermal expansion so much lower than metals?

Wood's thermal expansion parallel to the grain is dominated by the cellulose microfibrils, which are highly resistant to thermal expansion along their length — giving wood a CTE roughly one-third to one-quarter that of steel parallel to grain. Perpendicular to the grain, wood's thermal expansion is considerably higher (closer to some plastics) because it is governed by the softer lignin/hemicellulose matrix between fibers rather than the stiff cellulose fibers themselves — one of many ways wood's properties are highly direction-dependent (anisotropic).

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