C14 vs C18

C18 is 1.3 times as stiff as C14. It is 1.1 times as dense. Per unit mass C18 is 1.2 times as stiff. Strength: f_m,k = 14 MPa for C14, f_m,k = 18 MPa for C18.

C14 EN 338:2016 C18 EN 338:2016

Side by side

ratio = C18 / C14 · log scale

Property	C14	C18	Unit	Ratio
E₁ Modulus, direction 1	7	9	GPa	1.29×
E₂ Modulus, direction 2	0.23	0.3	GPa	1.3×
E₃ Modulus, direction 3	0.23	0.3	GPa	1.3×
G₁₂ Shear modulus 1-2	0.44	0.56	GPa	1.27×
G₁₃ Shear modulus 1-3	0.44	0.56	GPa	1.27×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	4.7	6	GPa	1.28×
ρ Density	350	380	kg/m³	1.09×
ρ_k Density, characteristic (5 % fractile)	290	320	kg/m³	1.1×
f_m,k Bending strength	14	18	MPa	1.29×
f_t,0,k Tension parallel to grain	7.2	10	MPa	1.39×
f_t,90,k Tension perpendicular to grain	0.4	0.4	MPa	1×
f_c,0,k Compression parallel to grain	16	18	MPa	1.12×
f_c,90,k Compression perpendicular to grain	2	2.2	MPa	1.1×
f_v,k Shear strength	3	3.4	MPa	1.13×
E/ρ Specific stiffness E/ρ · derived	20	23.68	MJ/kg	1.18×
c₀ Bar wave speed √(E/ρ) · derived	4472	4867	m/s	1.09×
f/ρ Specific strength f/ρ · derived	40	47.37	kJ/kg	1.18×

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.