AISI 205 (S20500) Stainless Steel
AISI 205 stainless steel is an austenitic stainless steel formulated for primary forming into wrought products. 205 is the AISI designation for this material. S20500 is the UNS number.
It has a fairly low base cost among wrought austenitic stainless steels. In addition, it can have a fairly high tensile strength and has a fairly low embodied energy.
The properties of AISI 205 stainless 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 AISI 205 stainless steel 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
210 to 440
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
11 to 51 %
Fatigue Strength
410 to 640 MPa 60 to 92 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
560 to 850 MPa 81 to 120 x 103 psi
Tensile Strength: Ultimate (UTS)
800 to 1430 MPa 120 to 210 x 103 psi
Tensile Strength: Yield (Proof)
450 to 1100 MPa 65 to 160 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
410 °C 770 °F
Maximum Temperature: Mechanical
880 °C 1620 °F
Melting Completion (Liquidus)
1380 °C 2520 °F
Melting Onset (Solidus)
1340 °C 2440 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Expansion
18 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
11 % relative
Density
7.6 g/cm3 470 lb/ft3
Embodied Carbon
2.6 kg CO2/kg material
Embodied Energy
37 MJ/kg 16 x 103 BTU/lb
Embodied Water
150 L/kg 18 gal/lb
Common Calculations
PREN (Pitting Resistance)
23
Resilience: Ultimate (Unit Rupture Work)
150 to 430 MJ/m3
Resilience: Unit (Modulus of Resilience)
510 to 3060 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
26 points
Strength to Weight: Axial
29 to 52 points
Strength to Weight: Bending
25 to 37 points
Thermal Shock Resistance
16 to 29 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 205 stainless steel is notable for containing a comparatively high amount of manganese (Mn). Manganese is used to improve ductility at elevated temperatures. It also permits a higher nitrogen content than would otherwise be possible.
| Fe | 62.6 to 68.1 | |
| Cr | 16.5 to 18.5 | |
| Mn | 14 to 15.5 | |
| Ni | 1.0 to 1.7 | |
| Si | 0 to 1.0 | |
| N | 0.32 to 0.4 | |
| C | 0.12 to 0.25 | |
| P | 0 to 0.060 | |
| 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 A666: Standard Specification for Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar
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
Austenitic Stainless Steels: Microstructure and Mechanical Properties, P. Marshall, 1984
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015