D55 vs D80

D80 is 1.5 times as stiff as D55. It is 1.4 times as dense. Per unit mass D80 is 1.1 times as stiff. Strength: f_m,k = 55 MPa for D55, f_m,k = 80 MPa for D80.

D55 EN 338:2016 D80 EN 338:2016

Side by side

ratio = D80 / D55 · log scale

Property	D55	D80	Unit	Ratio
E₁ Modulus, direction 1	15.5	24	GPa	1.55×
E₂ Modulus, direction 2	1.03	1.6	GPa	1.55×
E₃ Modulus, direction 3	1.03	1.6	GPa	1.55×
G₁₂ Shear modulus 1-2	0.97	1.5	GPa	1.55×
G₁₃ Shear modulus 1-3	0.97	1.5	GPa	1.55×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	13	20.2	GPa	1.55×
ρ Density	790	1080	kg/m³	1.37×
ρ_k Density, characteristic (5 % fractile)	660	900	kg/m³	1.36×
f_m,k Bending strength	55	80	MPa	1.45×
f_t,0,k Tension parallel to grain	33	48	MPa	1.45×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	32	38	MPa	1.19×
f_c,90,k Compression perpendicular to grain	6.6	13.5	MPa	2.05×
f_v,k Shear strength	4.7	5	MPa	1.06×
E/ρ Specific stiffness E/ρ · derived	19.62	22.22	MJ/kg	1.13×
c₀ Bar wave speed √(E/ρ) · derived	4429	4714	m/s	1.06×
f/ρ Specific strength f/ρ · derived	69.62	74.07	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.