D40 vs D45

D45 and D40 are about equally stiff. Their densities are about the same. Per unit mass they are about equally stiff (19.7 and 19.29 MJ/kg). Strength: f_m,k = 40 MPa for D40, f_m,k = 45 MPa for D45.

D40 EN 338:2016 D45 EN 338:2016

Side by side

ratio = D45 / D40 · log scale

Property	D40	D45	Unit	Ratio
E₁ Modulus, direction 1	13	13.5	GPa	1.04×
E₂ Modulus, direction 2	0.87	0.9	GPa	1.03×
E₃ Modulus, direction 3	0.87	0.9	GPa	1.03×
G₁₂ Shear modulus 1-2	0.81	0.84	GPa	1.04×
G₁₃ Shear modulus 1-3	0.81	0.84	GPa	1.04×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	10.9	11.3	GPa	1.04×
ρ Density	660	700	kg/m³	1.06×
ρ_k Density, characteristic (5 % fractile)	550	580	kg/m³	1.05×
f_m,k Bending strength	40	45	MPa	1.12×
f_t,0,k Tension parallel to grain	24	27	MPa	1.12×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	27	29	MPa	1.07×
f_c,90,k Compression perpendicular to grain	5.5	5.8	MPa	1.05×
f_v,k Shear strength	4.2	4.4	MPa	1.05×
E/ρ Specific stiffness E/ρ · derived	19.7	19.29	MJ/kg	0.979×
c₀ Bar wave speed √(E/ρ) · derived	4438	4392	m/s	0.99×
f/ρ Specific strength f/ρ · derived	60.61	64.29	kJ/kg	1.06×

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.