D55 vs D70

D70 is 1.3 times as stiff as D55. It is 1.2 times as dense. Per unit mass they are about equally stiff (19.62 and 20.83 MJ/kg). Strength: f_m,k = 55 MPa for D55, f_m,k = 70 MPa for D70.

D55 EN 338:2016 D70 EN 338:2016

Side by side

ratio = D70 / D55 · log scale

Property	D55	D70	Unit	Ratio
E₁ Modulus, direction 1	15.5	20	GPa	1.29×
E₂ Modulus, direction 2	1.03	1.33	GPa	1.29×
E₃ Modulus, direction 3	1.03	1.33	GPa	1.29×
G₁₂ Shear modulus 1-2	0.97	1.25	GPa	1.29×
G₁₃ Shear modulus 1-3	0.97	1.25	GPa	1.29×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	13	16.8	GPa	1.29×
ρ Density	790	960	kg/m³	1.22×
ρ_k Density, characteristic (5 % fractile)	660	800	kg/m³	1.21×
f_m,k Bending strength	55	70	MPa	1.27×
f_t,0,k Tension parallel to grain	33	42	MPa	1.27×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	32	36	MPa	1.12×
f_c,90,k Compression perpendicular to grain	6.6	12	MPa	1.82×
f_v,k Shear strength	4.7	5	MPa	1.06×
E/ρ Specific stiffness E/ρ · derived	19.62	20.83	MJ/kg	1.06×
c₀ Bar wave speed √(E/ρ) · derived	4429	4564	m/s	1.03×
f/ρ Specific strength f/ρ · derived	69.62	72.92	kJ/kg	1.05×

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.