What is AISI 303 material?
What is AISI 303 material?
Type 1.4305 stainless steel is commonly referred to as grade 303 stainless steel. Grade 303 stainless steel is the most machinable of all austenitic stainless steels. AISI 303 is an austenitic stainless steel with the addition of sulfur, making it an easy-to-machine grade and well-suited for components requiring heavy machining. It offers good corrosion resistance and mechanical properties in mildly corrosive environments, but its corrosion resistance is lower than that of 304 stainless steel and it is not recommended for use in marine environments. Common applications include nuts, bolts, gears, and precision-machined parts such as shafts and fittings.
chemical composition of stainless steel AISI 303 / 1.4305
|
C |
Si |
Mn |
P |
S |
N |
Cr |
Cu |
Mo |
Ni |
Ti |
|---|---|---|---|---|---|---|---|---|---|---|
|
≤ 0,10 |
≤ 1,00 |
≤ 2,00 |
≤ 0,045 |
0,15 - 0,35 |
≤ 0,10 |
17,0 - 19,0 |
≤ 1,00 |
- |
8,0 - 10,0 |
- |
AISI 303 stainless steel Physical properties
Magnetisability: low
Density (kg/dm³): 7.9
Thermal conductivity (at up to 20°C): 15
Specific heat capacity (at 20°C) in J/(kg K): 500
Electronic resistance at room temperature (in Ω mm²/m): 0.73
AISI 303 / 1.4305 stainless steel bar Mechanical properties
| Mechanical Properties | |||
| Hardness, Brinell | 228 | 228 | |
| Hardness, Knoop | 251 | 251 | Converted from Brinell hardness. |
| Hardness, Rockwell B | 96 | 96 | Converted from Brinell hardness. |
| Hardness, Rockwell C | 19 | 19 | Converted from Brinell hardness. Value below normal HRC range, for comparison only. |
| Hardness, Vickers | 240 | 240 | Converted from Brinell hardness. |
| Tensile Strength, Ultimate | 690 MPa | 100000 psi | |
| Tensile Strength, Yield | 415 MPa | 60200 psi | at 0.2% offset |
| Elongation at Break | 40 % | 40 % | in 50 mm |
| Modulus of Elasticity | 193 GPa | 28000 ksi | tension |
| Poisson's Ratio | 0.25 | 0.25 | Calculated |
| Fatigue Strength | 240 MPa | 34800 psi | annealed sample |
| Fatigue Strength | 330 MPa | 47900 psi | 25% hardened sample |
| Shear Modulus | 77.2 GPa | 11200 ksi | |
Corrosion Resistance
303 stainless steel offers decent corrosion resistance. It can perform well in environments with mild exposure to atmospheric conditions and weak acids. However, its resistance is lower than other stainless steel like 304. Because it contains sulfur content. That enhances its machinability but makes it easier to corrosion, particularly in chloride-rich or marine environments. It's suitable for many applications but is not ideal for highly corrosive or harsh conditions.
Heat Resistance
303 stainless steel can handle temperatures up to 870°C (1600°F) during intermittent use and up to 925°C (1700°F) during continuous use. Its heat resistance is moderate. Therefore, it is not ideal for extremely high-temperature environments. Other stainless steels like 304 or 316 offer better heat resistance.
Is 303 Stainless Steel Magnetic?
No. 303 stainless steel is generally considered non-magnetic in its annealed condition. This is typical for austenitic stainless steel.
Heat treatment and hot forming
Solution annealing (+AT) (cooling by air or water): 1000 - 1100 °C
Hot forming (cooling by air): 900 - 1200 °C
Which is better, 303 or 304 stainless steel?
The main difference is that 303 stainless steel is a free-machining alloy, containing added sulfur to make it easier to cut, while 304 stainless steel is more corrosion-resistant and better for applications that require welding and strength. 303 is ideal for intricate, machined parts like screws and bushings, whereas 304 is better suited for general-purpose use in harsh environments or where corrosion resistance is crucial, such as in food processing equipment or construction.
Gnee Steel offers a comprehensive range of AISI 303 products in a wide variety of specifications, all conforming to international standards such as ASTM, ISO, and EN. These products are commonly used in a variety of forms to meet diverse industrial applications. These include bars, rods, plates, tubes, wire, and fasteners such as bolts, nuts, and screws. For detailed chemical composition and free samples, please contact our factory today. We offer competitive pricing and excellent service.Email: info@gneestainless.com
