Educational material — not for design use. Every number cites its source; see provenance & disclaimers.

Materials

Stiffness is independent of strength — that's why a "stronger" alloy can deflect more. This chart plots Young's modulus against density (both log scales, Ashby-style); the table below carries every value's source, basis, and original published units.

Young's modulus vs density (log–log) Scatter of the materials database; classes share colors. Stiff-and-light is up and left. 100 300 1,000 3,000 10,000 30,000 0.1 1 10 100 1000 density ρ (kg/m³) Young's modulus E (GPa) AISI 1045 medium-carbon steel — E = 200 GPa, ρ = 7870 kg/m³ (Normalized bar (normalised per AS 1442 grade 1045, AISI 1045 equivalent; typical normalizing 840-920 C per supplier datasheets). ALL VALUES TYPICAL, not spec minimums — weakest-citation row. Elastic/physical properties are condition-independent typicals.) 1045 AISI 4340 low-alloy steel (Ni-Cr-Mo) — E = 200 GPa, ρ = 7833 kg/m³ (Quenched and tempered to Ftu = 260 ksi level per MIL-HDBK-5J Table 2.3.1.0(f1) (AMS 6414, consumable-electrode vacuum-melted; bar, forging, tubing; thickness limits per table footnote: <=1.70 in. martempered / <=2.50 in. oil quench / <=3.50 in. water quench, 200 ft/min flow). Elastic and physical properties are the single nominal values MIL-HDBK-5J lists for all Section 2.3 low-alloy steels (4130/4140/4340/8630 group).) 4340 ASTM A36 structural steel (hot-rolled) — E = 200 GPa, ρ = 7806 kg/m³ (Hot-rolled, as-rolled; strength minimums apply to plates/shapes/bars up to 8 in. thick (plates over 8 in. drop to 32 ksi yield)) A36 304 stainless steel — E = 193 GPa, ρ = 7889 kg/m³ (Annealed (ASTM A240 Condition A, sheet/strip/plate); physical properties at room temperature) 304 SS C26000 Cartridge Brass (70/30) — E = 110 GPa, ρ = 8525 kg/m³ (H02 (half-hard) temper, flat products (sheet/strip), 0.040 in section, typical values at 68°F (20°C). Elastic constants and density are temper-independent CDA values.) Brass 70/30 Ti-6Al-4V — E = 110 GPa, ρ = 4429 kg/m³ (Annealed; primary strength values are A-basis for sheet <= 0.1875 in per AMS 4911 / AMS-T-9046 Comp. AB-1 (MIL-HDBK-5J Table 5.4.1.0(b)); elastic/physical values from same table (sheet, strip, and plate)) Ti-6Al-4V Gray Cast Iron, ASTM A48 Class 30 — E = 90 GPa, ρ = 7141 kg/m³ (As-cast, classified by separately cast test bars per ASTM A48/A48M (Class 30 = 30 ksi min tensile)) Gray iron 2024-T3 aluminum sheet (bare) — E = 72 GPa, ρ = 2768 kg/m³ (T3, bare flat sheet 0.010-0.128 in. thick, AMS 4037 / AMS-QQ-A-250/4 (MIL-HDBK-5J Table 3.2.3.0(b1), p. 3-71)) 2024-T3 7075-T6 aluminum — E = 71 GPa, ρ = 2796 kg/m³ (T6 temper; design-minimum entries are bare sheet per QQ-A-250/12 (0.040-0.249 in, MIL-HDBK-5 lineage); typical entries are T6/T651 nominal values) 7075-T6 6061-T6 aluminum — E = 68 GPa, ρ = 2713 kg/m³ (T6 (and T62), sheet 0.010-0.249 in per AMS 4025/AMS 4027/AMS-QQ-A-250/11 for MIL-HDBK-5J design values; typical entries are generic T6 wrought-product values) 6061-T6 Normal-weight concrete, f'c = 4000 psi class — E = 25 GPa, ρ = 2323 kg/m³ (Normal-weight (plain), specified 28-day cylinder compressive strength f'c = 4000 psi, moist-cured per standard practice) Concrete Douglas-fir (coast) — E = 13 GPa, ρ = 480 kg/m³ (Clear, straight-grained small specimens at 12% moisture content; "Coast" Douglas-fir = grown in Oregon/Washington west of the Cascade Mountains summit (Wood Handbook Table 5-3 footnote e). Average values from species sampling — typical, not design minima.) Douglas-fir Nylon 6/6 (PA66), unfilled — E = 3.1 GPa, ρ = 1140 kg/m³ (Unfilled injection-molding resin (Celanese/DuPont Zytel 101L NC010), dry as molded (DAM), 23 C. Conditioned (50% RH) values noted per property — PA66 is strongly moisture-sensitive.) Nylon 6/6

aluminumcopper-alloyconcretecast-ironpolymerstainlesssteeltitaniumwood

The database

MaterialConditionProperty Published valueSIBasis Source
2024-T3 aluminum sheet (bare) T3, bare flat sheet 0.010-0.128 in. thick, AMS 4037 / AMS-QQ-A-250/4 (MIL-HDBK-5J Table 3.2.3.0(b1), p. 3-71) density 0.1 lb/inch**3 2768 kg/m³ typical mil-hdbk-5j
youngs modulus 10.5 Msi 72 GPa typical mil-hdbk-5j
poisson ratio 0.33 1 0.33 typical mil-hdbk-5j
shear modulus 4 Msi 28 GPa typical mil-hdbk-5j
yield strength 47 ksi 0.32 GPa design minimum mil-hdbk-5j
ultimate strength 64 ksi 0.44 GPa design minimum mil-hdbk-5j
ultimate strength 70 ksi 0.48 GPa typical united-aluminum-2024
coefficient of thermal expansion 12.7 1e-6/degF_interval 2.3e-14 GPa typical asm-desk-ed-1998
6061-T6 aluminum T6 (and T62), sheet 0.010-0.249 in per AMS 4025/AMS 4027/AMS-QQ-A-250/11 for MIL-HDBK-5J design values; typical entries are generic T6 wrought-product values density 0.098 lb/inch**3 2713 kg/m³ typical mil-hdbk-5j
youngs modulus 9.9 Msi 68 GPa typical mil-hdbk-5j
poisson ratio 0.33 1 0.33 typical mil-hdbk-5j
shear modulus 3.8 Msi 26 GPa typical mil-hdbk-5j
yield strength 36 ksi 0.25 GPa design minimum mil-hdbk-5j
yield strength 276 MPa 0.28 GPa typical jeelix-6061
ultimate strength 42 ksi 0.29 GPa design minimum mil-hdbk-5j
ultimate strength 310 MPa 0.31 GPa typical jeelix-6061
coefficient of thermal expansion 13 1e-6/degF_interval 2.3e-14 GPa typical asm-desk-ed-1998
7075-T6 aluminum T6 temper; design-minimum entries are bare sheet per QQ-A-250/12 (0.040-0.249 in, MIL-HDBK-5 lineage); typical entries are T6/T651 nominal values density 0.101 lb/inch**3 2796 kg/m³ typical nasa-cr-123773
youngs modulus 10.3 Msi 71 GPa typical nasa-cr-123773
poisson ratio 0.33 1 0.33 typical nasa-cr-123773
shear modulus 3.9 Msi 27 GPa typical nasa-cr-123773
yield strength 67 ksi 0.46 GPa design minimum nasa-cr-123773
ultimate strength 77 ksi 0.53 GPa design minimum nasa-cr-123773
yield strength 73000 psi 0.50 GPa typical gabrian-7075
ultimate strength 83000 psi 0.57 GPa typical gabrian-7075
coefficient of thermal expansion 12.9 1e-6/degF_interval 2.3e-14 GPa typical asm-desk-ed-1998
C26000 Cartridge Brass (70/30) H02 (half-hard) temper, flat products (sheet/strip), 0.040 in section, typical values at 68°F (20°C). Elastic constants and density are temper-independent CDA values. density 0.308 lb/inch**3 8525 kg/m³ typical cda-c26000
youngs modulus 16000 ksi 110 GPa typical cda-c26000
shear modulus 6000 ksi 41 GPa typical cda-c26000
poisson ratio 0.34 1 0.34 typical azom-6341
yield strength 52 ksi 0.36 GPa typical cda-c26000
ultimate strength 62 ksi 0.43 GPa typical cda-c26000
coefficient of thermal expansion 11.1 1e-6/degF_interval 2.0e-14 GPa typical cda-c26000
Normal-weight concrete, f'c = 4000 psi class Normal-weight (plain), specified 28-day cylinder compressive strength f'c = 4000 psi, moist-cured per standard practice density 145 lb/ft**3 2323 kg/m³ typical uofm-civl1101
compressive strength 4000 psi 0.028 GPa spec minimum uofm-civl1101
youngs modulus 3605000 psi 25 GPa typical aci-318-formula
poisson ratio 0.2 1 0.2 typical gilson-c469
Gray Cast Iron, ASTM A48 Class 30 As-cast, classified by separately cast test bars per ASTM A48/A48M (Class 30 = 30 ksi min tensile) ultimate strength 30 ksi 0.21 GPa spec minimum astm-a48
compressive strength 109 ksi 0.75 GPa typical penticton-a48-c30
youngs modulus 13 Msi 90 GPa typical asm-desk-ed-1998
poisson ratio 0.26 1 0.26 typical asm-via-amesweb
density 0.258 lb/inch**3 7141 kg/m³ typical penticton-a48-c30
coefficient of thermal expansion 10.5 1e-6/K 1.0e-14 GPa typical asm-desk-ed-1998
Nylon 6/6 (PA66), unfilled Unfilled injection-molding resin (Celanese/DuPont Zytel 101L NC010), dry as molded (DAM), 23 C. Conditioned (50% RH) values noted per property — PA66 is strongly moisture-sensitive. density 1140 kg/m**3 1140 kg/m³ typical celanese-zytel-101l
youngs modulus 3100 MPa 3.1 GPa typical celanese-zytel-101l
poisson ratio 0.37 1 0.37 typical celanese-zytel-101l
yield strength 82 MPa 0.082 GPa typical celanese-zytel-101l
ultimate strength 12300 psi 0.085 GPa typical ensinger-tecamid-66
304 stainless steel Annealed (ASTM A240 Condition A, sheet/strip/plate); physical properties at room temperature yield strength 30 ksi 0.21 GPa spec minimum astm-a240
ultimate strength 75 ksi 0.52 GPa spec minimum astm-a240
density 0.285 lb/inch**3 7889 kg/m³ typical rolled-alloys-304
youngs modulus 28 Msi 193 GPa typical ak-steel-304
poisson ratio 0.29 1 0.29 typical kmac-304
shear modulus 11.2 Msi 77 GPa typical ak-steel-304
coefficient of thermal expansion 9.2 1e-6/degF_interval 1.7e-14 GPa typical sandmeyer-304
AISI 1045 medium-carbon steel Normalized bar (normalised per AS 1442 grade 1045, AISI 1045 equivalent; typical normalizing 840-920 C per supplier datasheets). ALL VALUES TYPICAL, not spec minimums — weakest-citation row. Elastic/physical properties are condition-independent typicals. density 7.87 g/cm**3 7870 kg/m³ typical azom-6130
youngs modulus 200 GPa 200 GPa typical azom-6130
poisson ratio 0.29 1 0.29 typical azom-6130
shear modulus 80 GPa 80 GPa typical azom-6130
yield strength 410 MPa 0.41 GPa typical interlloy-1045
ultimate strength 640 MPa 0.64 GPa typical interlloy-1045
coefficient of thermal expansion 11.6 1e-6/K 1.2e-14 GPa typical asm-ready-ref
AISI 4340 low-alloy steel (Ni-Cr-Mo) Quenched and tempered to Ftu = 260 ksi level per MIL-HDBK-5J Table 2.3.1.0(f1) (AMS 6414, consumable-electrode vacuum-melted; bar, forging, tubing; thickness limits per table footnote: <=1.70 in. martempered / <=2.50 in. oil quench / <=3.50 in. water quench, 200 ft/min flow). Elastic and physical properties are the single nominal values MIL-HDBK-5J lists for all Section 2.3 low-alloy steels (4130/4140/4340/8630 group). density 0.283 lb/inch**3 7833 kg/m³ typical mil-hdbk-5j
youngs modulus 29 Msi 200 GPa typical mil-hdbk-5j
poisson ratio 0.32 1 0.32 typical mil-hdbk-5j
shear modulus 11 Msi 76 GPa typical mil-hdbk-5j
yield strength 217 ksi 1.5 GPa spec minimum mil-hdbk-5j
ultimate strength 260 ksi 1.8 GPa spec minimum mil-hdbk-5j
coefficient of thermal expansion 12.3 1e-6/K 1.2e-14 GPa typical asm-ready-ref
ASTM A36 structural steel (hot-rolled) Hot-rolled, as-rolled; strength minimums apply to plates/shapes/bars up to 8 in. thick (plates over 8 in. drop to 32 ksi yield) yield strength 36 ksi 0.25 GPa spec minimum astm-a36
ultimate strength 58 ksi 0.40 GPa spec minimum astm-a36
density 0.282 lb/inch**3 7806 kg/m³ typical fe-handbook-9-2
youngs modulus 29 Msi 200 GPa typical fe-handbook-9-2
poisson ratio 0.3 1 0.3 typical fe-handbook-9-2
shear modulus 11.5 Msi 79 GPa typical fe-handbook-9-2
coefficient of thermal expansion 11.7 1e-6/K 1.2e-14 GPa typical amesweb-metals
Ti-6Al-4V Annealed; primary strength values are A-basis for sheet <= 0.1875 in per AMS 4911 / AMS-T-9046 Comp. AB-1 (MIL-HDBK-5J Table 5.4.1.0(b)); elastic/physical values from same table (sheet, strip, and plate) density 0.16 lb/inch**3 4429 kg/m³ typical mil-hdbk-5j
youngs modulus 16 Msi 110 GPa typical mil-hdbk-5j
poisson ratio 0.31 1 0.31 typical mil-hdbk-5j
shear modulus 6.2 Msi 43 GPa typical mil-hdbk-5j
yield strength 126 ksi 0.87 GPa design minimum mil-hdbk-5j
ultimate strength 134 ksi 0.92 GPa design minimum mil-hdbk-5j
coefficient of thermal expansion 4.78 1e-6/degF_interval 8.6e-15 GPa typical asm-desk-ed-1998
Douglas-fir (coast) Clear, straight-grained small specimens at 12% moisture content; "Coast" Douglas-fir = grown in Oregon/Washington west of the Cascade Mountains summit (Wood Handbook Table 5-3 footnote e). Average values from species sampling — typical, not design minima. density 0.48 g/cm**3 480 kg/m³ typical wood-handbook-fpl-gtr-282
youngs modulus 1.95 Msi 13 GPa typical wood-handbook-fpl-gtr-282
poisson ratio 0.292 1 0.292 typical wood-handbook-fpl-gtr-282
modulus of rupture 12400 psi 0.085 GPa typical wood-handbook-fpl-gtr-282
compressive strength 7230 psi 0.050 GPa typical wood-handbook-fpl-gtr-282

Strength values shown in GPa where applicable read as fractions (e.g. 0.25 GPa = 250 MPa). Full citations on the attributions page.