C24 vs C40

C40 is 1.3 times as stiff as C24. It is 1.1 times as dense. Per unit mass C40 is 1.1 times as stiff. Strength: f_m,k = 24 MPa for C24, f_m,k = 40 MPa for C40.

C24 EN 338:2016 C40 EN 338:2016

Side by side

ratio = C40 / C24 · log scale

Property	C24	C40	Unit	Ratio
E₁ Modulus, direction 1	11	14	GPa	1.27×
E₂ Modulus, direction 2	0.37	0.47	GPa	1.27×
E₃ Modulus, direction 3	0.37	0.47	GPa	1.27×
G₁₂ Shear modulus 1-2	0.69	0.88	GPa	1.28×
G₁₃ Shear modulus 1-3	0.69	0.88	GPa	1.28×
E₀,₀₅ Modulus parallel to grain, 5 % fractile	7.4	9.4	GPa	1.27×
ρ Density	420	480	kg/m³	1.14×
ρ_k Density, characteristic (5 % fractile)	350	400	kg/m³	1.14×
f_m,k Bending strength	24	40	MPa	1.67×
f_t,0,k Tension parallel to grain	14.5	26	MPa	1.79×
f_t,90,k Tension perpendicular to grain	0.4	0.4	MPa	1×
f_c,0,k Compression parallel to grain	21	27	MPa	1.29×
f_c,90,k Compression perpendicular to grain	2.5	2.8	MPa	1.12×
f_v,k Shear strength	4	4	MPa	1×
E/ρ Specific stiffness E/ρ · derived	26.19	29.17	MJ/kg	1.11×
c₀ Bar wave speed √(E/ρ) · derived	5118	5401	m/s	1.06×
f/ρ Specific strength f/ρ · derived	57.14	83.33	kJ/kg	1.46×

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.