Hardened 440A Stainless Steel
Hardened AISI 440A is AISI 440A stainless steel in the hardened (H) condition. The graph bars on the material properties cards below compare hardened AISI 440A to: wrought martensitic stainless steels (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
Elastic (Young's, Tensile) Modulus
200 GPa 28 x 106 psi
Elongation at Break
5.0 %
Fatigue Strength
790 MPa 110 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
1040 MPa 150 x 103 psi
Tensile Strength: Ultimate (UTS)
1790 MPa 260 x 103 psi
Tensile Strength: Yield (Proof)
1650 MPa 240 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
400 °C 750 °F
Maximum Temperature: Mechanical
760 °C 1400 °F
Melting Completion (Liquidus)
1480 °C 2700 °F
Melting Onset (Solidus)
1370 °C 2500 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
23 W/m-K 13 BTU/h-ft-°F
Thermal Expansion
10 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.5 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.9 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.0 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.2 kg CO2/kg material
Embodied Energy
31 MJ/kg 13 x 103 BTU/lb
Embodied Water
120 L/kg 14 gal/lb
Common Calculations
PREN (Pitting Resistance)
18
Resilience: Ultimate (Unit Rupture Work)
87 MJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
65 points
Strength to Weight: Bending
43 points
Thermal Diffusivity
6.2 mm2/s
Thermal Shock Resistance
65 points
Alloy Composition
| Fe | 78.4 to 83.4 | |
| Cr | 16 to 18 | |
| C | 0.6 to 0.75 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| Mo | 0 to 0.75 | |
| P | 0 to 0.040 | |
| S | 0 to 0.015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Advanced Materials in Automotive Engineering, Jason Rowe (editor), 2012
ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels
Corrosion of Stainless Steels, A. John Sedriks, 1996
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010