D45 vs D55

D55 is 1.1 times as stiff as D45. It is 1.1 times as dense. Per unit mass they are about equally stiff (19.29 and 19.62 MJ/kg). Strength: f_m,k = 45 MPa for D45, f_m,k = 55 MPa for D55.

D45 EN 338:2016 D55 EN 338:2016

Side by side

ratio = D55 / D45 · log scale

Property	D45	D55	Unit	Ratio
E₁ Modulus, direction 1	13.5	15.5	GPa	1.15×
E₂ Modulus, direction 2	0.9	1.03	GPa	1.14×
E₃ Modulus, direction 3	0.9	1.03	GPa	1.14×
G₁₂ Shear modulus 1-2	0.84	0.97	GPa	1.15×
G₁₃ Shear modulus 1-3	0.84	0.97	GPa	1.15×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	11.3	13	GPa	1.15×
ρ Density	700	790	kg/m³	1.13×
ρ_k Density, characteristic (5 % fractile)	580	660	kg/m³	1.14×
f_m,k Bending strength	45	55	MPa	1.22×
f_t,0,k Tension parallel to grain	27	33	MPa	1.22×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	29	32	MPa	1.1×
f_c,90,k Compression perpendicular to grain	5.8	6.6	MPa	1.14×
f_v,k Shear strength	4.4	4.7	MPa	1.07×
E/ρ Specific stiffness E/ρ · derived	19.29	19.62	MJ/kg	1.02×
c₀ Bar wave speed √(E/ρ) · derived	4392	4429	m/s	1.01×
f/ρ Specific strength f/ρ · derived	64.29	69.62	kJ/kg	1.08×

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.