D50 vs D55

D55 is 1.1 times as stiff as D50. Their densities are about the same. Per unit mass they are about equally stiff (18.92 and 19.62 MJ/kg). Strength: f_m,k = 50 MPa for D50, f_m,k = 55 MPa for D55.

D50 EN 338:2016 D55 EN 338:2016

Side by side

ratio = D55 / D50 · log scale

Property	D50	D55	Unit	Ratio
E₁ Modulus, direction 1	14	15.5	GPa	1.11×
E₂ Modulus, direction 2	0.93	1.03	GPa	1.11×
E₃ Modulus, direction 3	0.93	1.03	GPa	1.11×
G₁₂ Shear modulus 1-2	0.88	0.97	GPa	1.1×
G₁₃ Shear modulus 1-3	0.88	0.97	GPa	1.1×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	11.8	13	GPa	1.1×
ρ Density	740	790	kg/m³	1.07×
ρ_k Density, characteristic (5 % fractile)	620	660	kg/m³	1.06×
f_m,k Bending strength	50	55	MPa	1.1×
f_t,0,k Tension parallel to grain	30	33	MPa	1.1×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	30	32	MPa	1.07×
f_c,90,k Compression perpendicular to grain	6.2	6.6	MPa	1.06×
f_v,k Shear strength	4.5	4.7	MPa	1.04×
E/ρ Specific stiffness E/ρ · derived	18.92	19.62	MJ/kg	1.04×
c₀ Bar wave speed √(E/ρ) · derived	4350	4429	m/s	1.02×
f/ρ Specific strength f/ρ · derived	67.57	69.62	kJ/kg	1.03×

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.