AISI 405 (S40500) Stainless Steel
AISI 405 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 405 is the AISI designation for this material. S40500 is the UNS number. Additionally, the British Standard (BS) designation is 405S17.
It has a fairly high thermal conductivity among wrought ferritic stainless steels. In addition, it has a moderately low base cost and a moderately low embodied energy.
The graph bars on the material properties cards below compare AISI 405 stainless steel to: wrought ferritic 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
170
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
22 %
Fatigue Strength
130 MPa 19 x 103 psi
Poisson's Ratio
0.28
Reduction in Area
51 %
Rockwell B Hardness
76
Shear Modulus
76 GPa 11 x 106 psi
Shear Strength
300 MPa 43 x 103 psi
Tensile Strength: Ultimate (UTS)
470 MPa 68 x 103 psi
Tensile Strength: Yield (Proof)
200 MPa 29 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
390 °C 740 °F
Maximum Temperature: Mechanical
820 °C 1500 °F
Melting Completion (Liquidus)
1530 °C 2790 °F
Melting Onset (Solidus)
1480 °C 2700 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
30 W/m-K 17 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
7.0 % relative
Calomel Potential
-210 mV
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.0 kg CO2/kg material
Embodied Energy
28 MJ/kg 12 x 103 BTU/lb
Embodied Water
100 L/kg 12 gal/lb
Common Calculations
PREN (Pitting Resistance)
13
Resilience: Ultimate (Unit Rupture Work)
84 MJ/m3
Resilience: Unit (Modulus of Resilience)
100 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
17 points
Strength to Weight: Bending
17 points
Thermal Diffusivity
8.1 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 405 stainless steel is notable for including aluminum (Al). Aluminum is used to improve oxidation resistance. It can also enhance the effects of heat treatment.
| Fe | 82.5 to 88.4 | |
| Cr | 11.5 to 14.5 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| Ni | 0 to 0.6 | |
| Al | 0.1 to 0.3 | |
| C | 0 to 0.080 | |
| P | 0 to 0.040 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A473: Standard Specification for Stainless Steel Forgings
ASTM A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
Advanced Materials in Automotive Engineering, Jason Rowe (editor), 2012
ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Corrosion of Stainless Steels, A. John Sedriks, 1996
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994