ASTM A372 Grade J Alloy Steel
ASTM A372 grade J steel is an alloy steel formulated for primary forming into wrought products. It has a moderately low embodied energy and a moderately low base cost among wrought alloy steels in the same category.
The properties of ASTM A372 grade J steel include five 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 A372 grade J 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
200 to 310
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
17 to 22 %
Fatigue Strength
310 to 570 MPa 45 to 82 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
410 to 630 MPa 60 to 91 x 103 psi
Tensile Strength: Ultimate (UTS)
650 to 1020 MPa 95 to 150 x 103 psi
Tensile Strength: Yield (Proof)
430 to 850 MPa 63 to 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1420 °C 2580 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
44 W/m-K 26 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.4 % relative
Density
7.8 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
51 L/kg 6.1 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
130 to 170 MJ/m3
Resilience: Unit (Modulus of Resilience)
500 to 1930 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
23 to 36 points
Strength to Weight: Bending
21 to 29 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
19 to 30 points
Alloy Composition
Among alloy steels, the composition of ASTM A372 grade J steel is notable for containing comparatively high amounts of chromium (Cr) and manganese (Mn). Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures). Manganese is used to improve hardenability, hot workability, and surface quality. There is some loss of ductility and weldability, however.
| Fe | 96.7 to 97.8 | |
| Cr | 0.8 to 1.2 | |
| Mn | 0.75 to 1.1 | |
| C | 0.35 to 0.5 | |
| Si | 0.15 to 0.35 | |
| Mo | 0.15 to 0.25 | |
| P | 0 to 0.015 | |
| S | 0 to 0.010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A372: Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015