D27 vs D55

D55 is 1.5 times as stiff as D27. It is 1.3 times as dense. Per unit mass D55 is 1.1 times as stiff. Strength: f_m,k = 27 MPa for D27, f_m,k = 55 MPa for D55.

D27 EN 338:2016 D55 EN 338:2016

Side by side

ratio = D55 / D27 · log scale

Property	D27	D55	Unit	Ratio
E₁ Modulus, direction 1	10.5	15.5	GPa	1.48×
E₂ Modulus, direction 2	0.7	1.03	GPa	1.47×
E₃ Modulus, direction 3	0.7	1.03	GPa	1.47×
G₁₂ Shear modulus 1-2	0.66	0.97	GPa	1.47×
G₁₃ Shear modulus 1-3	0.66	0.97	GPa	1.47×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	8.8	13	GPa	1.48×
ρ Density	610	790	kg/m³	1.3×
ρ_k Density, characteristic (5 % fractile)	510	660	kg/m³	1.29×
f_m,k Bending strength	27	55	MPa	2.04×
f_t,0,k Tension parallel to grain	16	33	MPa	2.06×
f_t,90,k Tension perpendicular to grain	0.6	0.6	MPa	1×
f_c,0,k Compression parallel to grain	22	32	MPa	1.45×
f_c,90,k Compression perpendicular to grain	5.1	6.6	MPa	1.29×
f_v,k Shear strength	3.8	4.7	MPa	1.24×
E/ρ Specific stiffness E/ρ · derived	17.21	19.62	MJ/kg	1.14×
c₀ Bar wave speed √(E/ρ) · derived	4149	4429	m/s	1.07×
f/ρ Specific strength f/ρ · derived	44.26	69.62	kJ/kg	1.57×

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.