C18 vs C22

C22 is 1.1 times as stiff as C18. It is 1.1 times as dense. Per unit mass they are about equally stiff (23.68 and 24.39 MJ/kg). Strength: f_m,k = 18 MPa for C18, f_m,k = 22 MPa for C22.

C18 EN 338:2016 C22 EN 338:2016

Side by side

ratio = C22 / C18 · log scale

Property	C18	C22	Unit	Ratio
E₁ Modulus, direction 1	9	10	GPa	1.11×
E₂ Modulus, direction 2	0.3	0.33	GPa	1.1×
E₃ Modulus, direction 3	0.3	0.33	GPa	1.1×
G₁₂ Shear modulus 1-2	0.56	0.63	GPa	1.12×
G₁₃ Shear modulus 1-3	0.56	0.63	GPa	1.12×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	6	6.7	GPa	1.12×
ρ Density	380	410	kg/m³	1.08×
ρ_k Density, characteristic (5 % fractile)	320	340	kg/m³	1.06×
f_m,k Bending strength	18	22	MPa	1.22×
f_t,0,k Tension parallel to grain	10	13	MPa	1.3×
f_t,90,k Tension perpendicular to grain	0.4	0.4	MPa	1×
f_c,0,k Compression parallel to grain	18	20	MPa	1.11×
f_c,90,k Compression perpendicular to grain	2.2	2.4	MPa	1.09×
f_v,k Shear strength	3.4	3.8	MPa	1.12×
E/ρ Specific stiffness E/ρ · derived	23.68	24.39	MJ/kg	1.03×
c₀ Bar wave speed √(E/ρ) · derived	4867	4939	m/s	1.01×
f/ρ Specific strength f/ρ · derived	47.37	53.66	kJ/kg	1.13×

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.