D18 vs D50

D50 is 1.5 times as stiff as D18. It is 1.3 times as dense. Per unit mass D50 is 1.1 times as stiff. Strength: f_m,k = 18 MPa for D18, f_m,k = 50 MPa for D50.

D18 EN 338:2016 D50 EN 338:2016

Side by side

ratio = D50 / D18 · log scale

Property	D18	D50	Unit	Ratio
E₁ Modulus, direction 1	9.5	14	GPa	1.47×
E₂ Modulus, direction 2	0.63	0.93	GPa	1.48×
E₃ Modulus, direction 3	0.63	0.93	GPa	1.48×
G₁₂ Shear modulus 1-2	0.59	0.88	GPa	1.49×
G₁₃ Shear modulus 1-3	0.59	0.88	GPa	1.49×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	8	11.8	GPa	1.48×
ρ Density	570	740	kg/m³	1.3×
ρ_k Density, characteristic (5 % fractile)	475	620	kg/m³	1.31×
f_m,k Bending strength	18	50	MPa	2.78×
f_t,0,k Tension parallel to grain	11	30	MPa	2.73×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	18	30	MPa	1.67×
f_c,90,k Compression perpendicular to grain	4.8	6.2	MPa	1.29×
f_v,k Shear strength	3.5	4.5	MPa	1.29×
E/ρ Specific stiffness E/ρ · derived	16.67	18.92	MJ/kg	1.14×
c₀ Bar wave speed √(E/ρ) · derived	4082	4350	m/s	1.07×
f/ρ Specific strength f/ρ · derived	31.58	67.57	kJ/kg	2.14×

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.