AISI 303 (S30300) Stainless Steel
AISI 303 stainless steel is an austenitic stainless steel formulated for primary forming into wrought products. 303 is the AISI designation for this material. S30300 is the UNS number. Additionally, the British Standard (BS) designation is 303S21.
It has a moderately low embodied energy among the wrought austenitic stainless steels in the database.
The properties of AISI 303 stainless steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare AISI 303 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
170 to 210
Elastic (Young's, Tensile) Modulus
200 GPa 28 x 106 psi
Elongation at Break
40 to 51 %
Fatigue Strength
230 to 360 MPa 33 to 52 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
430 to 470 MPa 62 to 69 x 103 psi
Tensile Strength: Ultimate (UTS)
600 to 690 MPa 87 to 100 x 103 psi
Tensile Strength: Yield (Proof)
230 to 420 MPa 34 to 60 x 103 psi
Thermal Properties
Latent Heat of Fusion
290 J/g
Maximum Temperature: Corrosion
410 °C 780 °F
Maximum Temperature: Mechanical
930 °C 1700 °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 9.4 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.8 % 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
42 MJ/kg 18 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
18
Resilience: Ultimate (Unit Rupture Work)
240 MJ/m3
Resilience: Unit (Modulus of Resilience)
140 to 440 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
21 to 25 points
Strength to Weight: Bending
20 to 22 points
Thermal Diffusivity
4.4 mm2/s
Thermal Shock Resistance
13 to 15 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 303 stainless steel is notable for containing comparatively high amounts of nickel (Ni) and chromium (Cr). Nickel is primarily used to achieve a specific microstructure. In addition, it has a beneficial effect on mechanical properties and certain types of corrosion. Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance.
| Fe | 67.3 to 74.9 | |
| Cr | 17 to 19 | |
| Ni | 8.0 to 10 | |
| Mn | 0 to 2.0 | |
| Si | 0 to 1.0 | |
| S | 0.15 to 0.35 | |
| P | 0 to 0.2 | |
| C | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A895: Standard Specification for Free-Machining Stainless Steel Plate, Sheet, and Strip
ASTM A473: Standard Specification for Stainless Steel Forgings
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
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
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010