ASTM A209 Carbon-Molybdenum Steel
ASTM A209 steel is an alloy steel formulated for primary forming into wrought products. It has a very low electrical conductivity among wrought alloy steels in the same category. In addition, it has a very high ductility and can have a very low tensile strength.
The properties of ASTM A209 steel include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare ASTM A209 steel to: wrought alloy steels in the same category (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
140 to 150
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
34 %
Fatigue Strength
180 to 200 MPa 25 to 29 x 103 psi
Poisson's Ratio
0.29
Rockwell B Hardness
77 to 81
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
280 to 310 MPa 40 to 45 x 103 psi
Tensile Strength: Ultimate (UTS)
420 to 460 MPa 60 to 67 x 103 psi
Tensile Strength: Yield (Proof)
220 to 250 MPa 32 to 36 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
410 °C 760 °F
Melting Completion (Liquidus)
1470 °C 2670 °F
Melting Onset (Solidus)
1420 to 1430 °C 2600 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
50 W/m-K 29 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.1 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.1 to 8.2 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.4 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.5 kg CO2/kg material
Embodied Energy
20 MJ/kg 8.6 x 103 BTU/lb
Embodied Water
47 L/kg 5.6 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
120 to 130 MJ/m3
Resilience: Unit (Modulus of Resilience)
130 to 170 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
15 to 16 points
Strength to Weight: Bending
16 to 17 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
12 to 14 points
Followup Questions
Further Reading
ASTM A209: Standard Specification for Seamless Carbon-Molybdenum Alloy-Steel Boiler and Superheater Tubes
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015