ASTM A209 Grade T1a C-Mo Steel
ASTM A209 grade T1a is a type of ASTM A209 steel. Cited properties are appropriate for the normalized condition. It has the highest strength compared to the other variants of ASTM A209 steel.
The graph bars on the material properties cards below compare ASTM A209 grade T1a 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
150
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
34 %
Fatigue Strength
200 MPa 29 x 103 psi
Poisson's Ratio
0.29
Rockwell B Hardness
81
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
310 MPa 45 x 103 psi
Tensile Strength: Ultimate (UTS)
460 MPa 67 x 103 psi
Tensile Strength: Yield (Proof)
250 MPa 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 °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)
8.2 % 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)
130 MJ/m3
Resilience: Unit (Modulus of Resilience)
170 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
16 points
Strength to Weight: Bending
17 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
14 points
Alloy Composition
| Fe | 97.8 to 99.01 | |
| Mn | 0.3 to 0.8 | |
| Mo | 0.44 to 0.65 | |
| Si | 0.1 to 0.5 | |
| C | 0.15 to 0.25 | |
| P | 0 to 0.025 | |
| S | 0 to 0.025 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
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