C18 vs C50

C50 is 1.8 times as stiff as C18. It is 1.4 times as dense. Per unit mass C50 is 1.3 times as stiff. Strength: f_m,k = 18 MPa for C18, f_m,k = 50 MPa for C50.

C18 EN 338:2016 C50 EN 338:2016

Side by side

ratio = C50 / C18 · log scale

Property	C18	C50	Unit	Ratio
E₁ Modulus, direction 1	9	16	GPa	1.78×
E₂ Modulus, direction 2	0.3	0.53	GPa	1.77×
E₃ Modulus, direction 3	0.3	0.53	GPa	1.77×
G₁₂ Shear modulus 1-2	0.56	1	GPa	1.79×
G₁₃ Shear modulus 1-3	0.56	1	GPa	1.79×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	6	10.7	GPa	1.78×
ρ Density	380	520	kg/m³	1.37×
ρ_k Density, characteristic (5 % fractile)	320	430	kg/m³	1.34×
f_m,k Bending strength	18	50	MPa	2.78×
f_t,0,k Tension parallel to grain	10	33.5	MPa	3.35×
f_t,90,k Tension perpendicular to grain	0.4	0.4	MPa	1×
f_c,0,k Compression parallel to grain	18	30	MPa	1.67×
f_c,90,k Compression perpendicular to grain	2.2	3	MPa	1.36×
f_v,k Shear strength	3.4	4	MPa	1.18×
E/ρ Specific stiffness E/ρ · derived	23.68	30.77	MJ/kg	1.3×
c₀ Bar wave speed √(E/ρ) · derived	4867	5547	m/s	1.14×
f/ρ Specific strength f/ρ · derived	47.37	96.15	kJ/kg	2.03×

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.