Half-Hard 304 Stainless Steel
Half-hard AISI 304 is AISI 304 stainless steel in the half-hard temper. It has the highest strength and lowest ductility compared to the other variants of AISI 304 stainless steel. The graph bars on the material properties cards below compare half-hard AISI 304 to: wrought austenitic 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
Brinell Hardness
360
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
8.0 %
Fatigue Strength
440 MPa 63 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
690 MPa 100 x 103 psi
Tensile Strength: Ultimate (UTS)
1180 MPa 170 x 103 psi
Tensile Strength: Yield (Proof)
860 MPa 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
290 J/g
Maximum Temperature: Corrosion
420 °C 790 °F
Maximum Temperature: Mechanical
710 °C 1300 °F
Melting Completion (Liquidus)
1450 °C 2640 °F
Melting Onset (Solidus)
1400 °C 2550 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
16 W/m-K 9.2 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
15 % relative
Calomel Potential
-80 mV
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
3.0 kg CO2/kg material
Embodied Energy
43 MJ/kg 18 x 103 BTU/lb
Embodied Water
150 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
20
Resilience: Ultimate (Unit Rupture Work)
86 MJ/m3
Resilience: Unit (Modulus of Resilience)
1870 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
42 points
Strength to Weight: Bending
32 points
Thermal Diffusivity
4.2 mm2/s
Thermal Shock Resistance
25 points
Alloy Composition
| Fe | 66.5 to 74 | |
| Cr | 18 to 20 | |
| Ni | 8.0 to 10.5 | |
| Mn | 0 to 2.0 | |
| Si | 0 to 0.75 | |
| N | 0 to 0.1 | |
| C | 0 to 0.080 | |
| P | 0 to 0.045 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM A666: Standard Specification for Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar
ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service
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 Austenitic Stainless Steels: Mechanism, Mitigation and Monitoring, H. S. Khatak and B. Raj (editors), 2002
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Austenitic Stainless Steels: Microstructure and Mechanical Properties, P. Marshall, 1984
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994