properties of c-40 steel

Component Wt. %


C 0.37 - 0.44
Fe 98.6 - 99
Mn 0.6 - 0.9
P Max 0.04
S Max 0.05


Material Notes:
Typical uses include machine, plow, and carriage bolts, tie wire, cylinder head studs, and machined parts, U-bolts, concrete reinforcing rods, forgings, and non-critical springs.

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Physical Properties Metric English Comments


Density 7.845 g/cc 0.283 lb/in³ Chemical composition of 0.435% C, 0.69% Mn, 0.20% Si, annealed at 860°C (1580°F).

Mechanical Properties


Hardness, Brinell 170 170
Hardness, Knoop 191 191 Converted from Brinell hardness.
Hardness, Rockwell B 86 86 Converted from Brinell hardness.
Hardness, Vickers 178 178 Converted from Brinell hardness.
Tensile Strength, Ultimate 620 MPa 89900 psi
Tensile Strength, Yield 550 MPa 79800 psi
Elongation at Break 12 % 12 % in 50 mm
Reduction of Area 35 % 35 %
Modulus of Elasticity 200 GPa 29000 ksi Typical for steel
Bulk Modulus 140 GPa 20300 ksi Typical for steels
Poisson's Ratio 0.29 0.29 Typical For Steel
Izod Impact 49 J 36.1 ft-lb as rolled, 45 J (33 ft-lb) annealed at 790°C (1450°F), 65 J (48 ft-lb) normalized at 900°C (1650°F)
Shear Modulus 80 GPa 11600 ksi Typical for steels

Electrical Properties


Electrical Resistivity 1.71e-005 ohm-cm 1.71e-005 ohm-cm 20°C (68°F)
Electrical Resistivity at Elevated Temperature 0.0001111 ohm-cm 0.0001111 ohm-cm 800°C (1470°F)
Electrical Resistivity at Elevated Temperature 0.0001149 ohm-cm 0.0001149 ohm-cm 900°C (1650°F)
Electrical Resistivity at Elevated Temperature 0.0001179 ohm-cm 0.0001179 ohm-cm 1000°C
Electrical Resistivity at Elevated Temperature 2.21e-005 ohm-cm 2.21e-005 ohm-cm 100°C (212°F)
Electrical Resistivity at Elevated Temperature 2.96e-005 ohm-cm 2.96e-005 ohm-cm 200°C (390°F)
Electrical Resistivity at Elevated Temperature 4.93e-005 ohm-cm 4.93e-005 ohm-cm 400°C (750°F)
Electrical Resistivity at Elevated Temperature 7.63e-005 ohm-cm 7.63e-005 ohm-cm 600°C (1110°F)
Electrical Resistivity at Elevated Temperature 9.32e-005 ohm-cm 9.32e-005 ohm-cm 700°C (1290°F)

Thermal Properties


CTE, linear 20°C 11.3 µm/m-°C 6.28 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu.; 20-100°C (68-212°F)
CTE, linear 20°C 12.1 µm/m-°C 6.72 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu.; 20-200°C (68-390°F)
CTE, linear 250°C 12.2 µm/m-°C 6.78 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu; 20-300°C (68-570°F)
CTE, linear 250°C 13.3 µm/m-°C 7.39 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu; 20-400°C (68-750°F)
CTE, linear 500°C 13.9 µm/m-°C 7.72 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu; 20-500°C (68-930°F)
CTE, linear 500°C 14.2 µm/m-°C 7.89 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu; 20-600°C (68-1110°F)
CTE, linear 500°C 14.8 µm/m-°C 8.22 µin/in-°F Composition of 0.40% C, 0.11% Mn, 0.01% P, 0.03% S, 0.03% Si, 0.03% Cu; 20-700°C (68-1290°F)
CTE, linear 1000°C 14.7 µm/m-°C 8.17 µin/in-°F Typical steel
Specific Heat Capacity 0.486 J/g-°C 0.116 BTU/lb-°F 50-100°C (122-212°F)
Specific Heat Capacity at Elevated Temperature 0.515 J/g-°C 0.123 BTU/lb-°F 150-200°C (300-390°F)
Specific Heat Capacity at Elevated Temperature 0.528 J/g-°C 0.126 BTU/lb-°F 200-250°C (390-480°F)
Specific Heat Capacity at Elevated Temperature 0.548 J/g-°C 0.131 BTU/lb-°F 250-300°C (480-570°F)
Specific Heat Capacity at Elevated Temperature 0.569 J/g-°C 0.136 BTU/lb-°F 300-350°C (570-660°F)
Specific Heat Capacity at Elevated Temperature 0.586 J/g-°C 0.14 BTU/lb-°F 350-400°C (660-750°F)
Specific Heat Capacity at Elevated Temperature 0.624 J/g-°C 0.149 BTU/lb-°F 750-800°C (1380-1470°F)
Specific Heat Capacity at Elevated Temperature 0.649 J/g-°C 0.155 BTU/lb-°F 450-500°C (750-930°F)
Specific Heat Capacity at Elevated Temperature 0.708 J/g-°C 0.169 BTU/lb-°F 550-600°C (1020-1110°F)
Specific Heat Capacity at Elevated Temperature 0.77 J/g-°C 0.184 BTU/lb-°F 650-700°C (1200-1290°F)
Specific Heat Capacity at Elevated Temperature 1.583 J/g-°C 0.378 BTU/lb-°F 700-750°C (1290-1380°F)
Thermal Conductivity 50.7 W/m-K 352 BTU-in/hr-ft²-°F 100°C (212°F)
Thermal Conductivity 51.9 W/m-K 360 BTU-in/hr-ft²-°F 0°C
Thermal Conductivity at Elevated Temperature 24.7 W/m-K 171 BTU-in/hr-ft²-°F 800°C
Thermal Conductivity at Elevated Temperature 29.8 W/m-K 207 BTU-in/hr-ft²-°F 1200°C (2190°F)
Thermal Conductivity at Elevated Temperature 30.1 W/m-K 209 BTU-in/hr-ft²-°F 700°C (1290°F)
Thermal Conductivity at Elevated Temperature 32.9 W/m-K 228 BTU-in/hr-ft²-°F 1000°C (1830°F)
Thermal Conductivity at Elevated Temperature 33.9 W/m-K 235 BTU-in/hr-ft²-°F 600°C (1110°F)
Thermal Conductivity at Elevated Temperature 38.2 W/m-K 265 BTU-in/hr-ft²-°F 500°C (930°F)
Thermal Conductivity at Elevated Temperature 41.7 W/m-K 289 BTU-in/hr-ft²-°F 400°C (750°F)
Thermal Conductivity at Elevated Temperature 45.7 W/m-K 317 BTU-in/hr-ft²-°F 300°C (570°F)
Thermal Conductivity at Elevated Temperature 48.1 W/m-K 334 BTU-in/hr-ft²-°F 200°C (390°F)