D30 vs D40

D40 is 1.2 times as stiff as D30. Their densities are about the same. Per unit mass D40 is 1.1 times as stiff. Strength: f_m,k = 30 MPa for D30, f_m,k = 40 MPa for D40.

D30 EN 338:2016 D40 EN 338:2016

Side by side

ratio = D40 / D30 · log scale

Property	D30	D40	Unit	Ratio
E₁ Modulus, direction 1	11	13	GPa	1.18×
E₂ Modulus, direction 2	0.73	0.87	GPa	1.19×
E₃ Modulus, direction 3	0.73	0.87	GPa	1.19×
G₁₂ Shear modulus 1-2	0.69	0.81	GPa	1.17×
G₁₃ Shear modulus 1-3	0.69	0.81	GPa	1.17×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	9.2	10.9	GPa	1.18×
ρ Density	640	660	kg/m³	1.03×
ρ_k Density, characteristic (5 % fractile)	530	550	kg/m³	1.04×
f_m,k Bending strength	30	40	MPa	1.33×
f_t,0,k Tension parallel to grain	18	24	MPa	1.33×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	24	27	MPa	1.12×
f_c,90,k Compression perpendicular to grain	5.3	5.5	MPa	1.04×
f_v,k Shear strength	3.9	4.2	MPa	1.08×
E/ρ Specific stiffness E/ρ · derived	17.19	19.7	MJ/kg	1.15×
c₀ Bar wave speed √(E/ρ) · derived	4146	4438	m/s	1.07×
f/ρ Specific strength f/ρ · derived	46.88	60.61	kJ/kg	1.29×

Values at the first thickness band or product form of each material (EN 338:2016; EN 338:2016). A minimum and a characteristic value are not the same kind of number — read the ratio as a guide. Each material's page lists every band and every source.